


Ashes to Ashes

by TygerRises



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Byleth is the Ashen Demon, Demon Summoning, Enemies to Lovers, Eventual Skippable Smut, F/M, Garreg Mach is WAY in over their heads, Other Additional Tags to Be Added, Priest/Demon AU, Seteth Spoilers, Seteth is Rhea's Head Priest, Slow Burn, fe3h - Freeform, fe3h spoilers, fire emblem three houses au, no beta we die like Glenn
Language: English
Status: In-Progress
Published: 2020-01-03
Updated: 2020-10-03
Packaged: 2021-02-27 12:08:50
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 17
Words: 74,448
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22096906
Author URL: https://archiveofourown.org/users/TygerRises/pseuds/TygerRises
Summary: When Dimitri and Claude decide to take matters into their own hands to protect a war-torn Garreg Mach and a comatose Rhea,  their last-ditch efforts fall to demon summoning. The problem is, they didn't expect it to actually work. The Ashen Demon is a force to be reckoned with, and the only one strong enough to bind her is Rhea's right-hand priest Seteth.FE3H Demon/Priest AU
Relationships: My Unit | Byleth & Seteth, My Unit | Byleth/Seteth
Comments: 324
Kudos: 348





	1. The Ashen Demon

The massive, stone walls of Garreg Mach Monastery trembled with loud groans as the slew of dark beasts threw their mass against them. In mere moments the East wall would fall, and the Monastery in its entirety would be under attack. While it was home to the largest Priest institution in all of Fodlan, there were doubts that their force would be enough without the assistance of the Archbishop, Lady Rhea. 

"Dimitri, come on!" Claude hissed, panting as he slammed the door to their dorm room. The heavy metal lock clicked into place, securing them inside for a moment. If all went well, they'd have _just_ enough time.

"I'm trying!" The blonde retorted, stripping off his outer robes to avoid further blasphemy, trembling fingers grappling for a piece of chalk to draw on the floor. 

They were Priests in Training at Garreg Mach, tops of their class, but there wouldn't be an academy if something wasn't done about the battle ahead. Claude fingered through a hefty tome, coughing as dust scattered with each page. Fear was making him careless, skipping pages rather than checking for the circle they needed. 

"How did you even _find_ that, Claude?" Dimitri's voice shook, nerves rattling the usually level-headed boy. Any texts that had to do with demons, outside of proper slaying techniques (holy water and sacred ground, to name a few), were forbidden. To have such a text with the instructions for what they were about to attempt... The thought only continued to worry the young lion. 

Claude's dismissed the thought with a wave of his hand, a non-committal gesture that did absolutely _nothing_ to ease Dimitri's nerves. "Don't worry about it. Worry about-" He ripped a page out of the book and thrust it towards Dimitri. "-this. We need this on the floor, and your circle work is much better than mine. I've got everything else we need." 

Dimitri didn't know what the circle in question would summon, but Claude seemed to have everything under control. All he could do was hope his comrade knew what he was doing. "I'm not going to pretend I know what you're about to do; I just hope it works. This would be your greatest scheme yet. We save Garreg Mach and Rhea." Without another word, Dimitri began drawing the intricate summoning circle on their stone dorm floor, sweat beading on his forehead as he worked. 

The strange beasts had shown up only a few weeks ago, gathering en masse but never quite approaching the Monastery. Archbishop Rhea and her advisor, High Priest Seteth, had taken the necessary precautions to ensure that Garreg Mach was ready for combat when the time came (Seteth was sure they were not here for tea, per his exact words) but that was before Lady Rhea fell ill. 

It had happened within the span of an evening. That morning Lady Rhea was fine: chipper and conversational. After the feast bells tolled, Seteth had gone to rouse her from her Chambers, where she had fallen asleep.

Where she remained asleep, weeks later. 

Seteth had stepped in to take over while the rest of the Monastery worked on finding the sickness that had taken Lady Rhea, as well as its cure. The most popular theory was that it had been brought by the demonic beasts outside, but without a demon to study, they had no chance of concocting a cure. While what they were about to do was _obscenely_ forbidden, to Claude, it seemed like the only choice. 

"Okay, one last time. We summon the demon, use it to help us fight against the demons that are attacking _now,_ and then study it to get the cure. Seteth banishes it, and Rhea gets cured. Any questions?"

"Yes, where does the part where our robes are burned, and we're ostracized from the Church fit in?"

"Sorry, that part was replaced with our medal ceremony and ascension to Archbishops of awesome." 

Dimitri's jaw hung slack as he gaped at Claude and his calm nature. He slowly rose, brushing off his arms to inspect his handiwork. The circle was undoubtedly complicated, circles and patterns interweaving withing each other, all careful not to leave the outline of the ring itself. Every second he stared at this abomination on the floor made him feel worse, physically sick to his stomach. "It... it's done." Shame dripped off of the words, but Claude was unphased. 

"Perfect. My turn." The student ignored his trembling hands as he reached into a bag, pulling out multiple bags of reagents. Salt, charcoal, a goat's heart-

"Where in the _infinite hells_ did you get that?" By the way Dimitri's voice had cracked Claude assumed it was the first time he'd seen an animal heart. That, or he just hadn't expected it to be part of a _demonic_ _ritual_.

He rolled the clear bag that contained the heart over in his hand as if inspecting it himself. "Found it." 

"Where?!" 

"In a goat." Claude's cheeky humor was a welcome distraction, but their impending doom kept the air heavy. Even now, they could hear Seteth shouting commands outside in the central courtyards. Their classmates were gathering, as were the Knights of the Church, and Seteth himself atop a monstrous Wyvern. 

Claude's careful hands scattered the salt in various places before dragging the charcoal over specific, indicated spots. The heart was placed in the center, gently unwrapped. A bit of blood got onto the floor, causing Dimitri to shake his head. "We're never going to get that off of the stone." 

A few other herbs were scattered, things Claude had never heard of but were available when he pried the traveling merchants. It was amazing what you could get away with when you had enough coin. "If you think that's bad, you're not going to like this part." The slight scrape of metal against metal broke the tension as Claude unsheathed a dagger.

_BOOM._

_BOOM._

_BOOM._

The beasts outside were relentless. Each thundering echo hung in the air, all within earshot anxious. Would this be the impact that finally shattered the wall?

They didn't have much time left. 

"Claude... if we do this, we can't go back. The moment your blood hits that seal, we, and by extension, our kingdoms, are forever changed." Dimitri's hands shook nervously, the time constraint heavy on his mind.

"I know." The knife hung over his dark skin, waiting.

Anxious eyes searched Claude's face for an ounce of unease. When he didn't find any, Dimitri's shoulders sagged. "I trust you."

Claude flashed a grin, despite the situation. "I know."

_BOOM._

_BOOM._

**_CRASH._ **

The East Wall teetered, slowly crumbling in on itself in a loud crash. The stones plummeted to the ground, rubble stacking and scattering as the waves of demonic beasts began to invade. 

"Claude! Now!"

" _I know! Help_ them! I've got this!" He hissed, building up the courage to go through with the deed. Dimitri gritted his teeth, watching Claude hold the knife and arm over what would hopefully be their salvation (Goddess forgive him) before eventually nodding. He slipped his robes back on and exited the dorm without a second glance, left hand bright with magic, right hand grabbing at a lance outside. 

Once he was gone and the door closed, Claude growled and pinched the bridge of his nose in frustration. "Okay, okay. For Rhea, and Garreg Mach. And Fodlan." The knife seemed almost to glow as he sliced his arm open to drip onto the seal below. There was no going back now. The ground shook as beasts attacked outside, the sounds of battle filling the air even though the heavy doors and walls. The moment the first drop connected with the area within the circle, light flooded the dark dorm room. Magic poured out from the ring, splashing against the ground and furniture like ocean waves. Though it rippled and ebbed like water, nothing was wet. Well, nothing besides Claude's arm. Blood continued to flow, the thick red liquid pooling slowly until all of the circle was covered. Once Claude's blood had swallowed all the chalk, time itself seemed to stop. 

There was absolutely no sound. Was Claude even breathing? His chest rose and fell with each terrified breath, but there were no sounds of the battle outside, and no crashing waves of magic inside his room. Even the constant drip from his arm had been silenced. Upon second glance, his arm bore no mark, as though he'd never so much as scratched or bruised it. He looked around the room, confused. 

"I... I don't understand." 

" **Oh, but you will.** " A powerful voice boomed from behind him, within the confines of the circle. What Claude would have called a woman stood within the bloody prison, were it not for her monstrous horns and thick tail. Her piercing eyes seemed to glow as they watched his every move, slits instead of pupils flicking back and forth whenever Claude so much as twitched. " **You are the one that summoned me, yes?** " The tip of her tail flicked back and forth, much like the cats he'd seen on the Monastery grounds do right before - Claude gulped- pouncing.

He did his best to collect his worry, straightening his shirt with a smirk. "Yes. I am Claude von Riegan. I'd say it's a pleasure, but you know how it goes." 

The demon's tail stopped as she casually bent down to pick up the heart at her seemingly ordinary feet. " **Indeed. Mortals typically don't resort to such measures without great need. I have stopped time for our convenience, but do make it quick.** " She lifted the heart to her face to take a bite. Claude's stomach flipped as he let out a cough, though it sounded like a whimper.

"Excuse me, you... stopped time?" He looked around incredulously, hardly believing what he'd been told. His heart thudded against his chest. _Keep it together, Claude. I'm sure they can smell fear._

Half of the heart had already been consumed by the time she responded. She seemed unbothered by the blood that dripped down her chin and arm. If Claude didn't know any better, he'd assume she was toying with him. " **Yes. The battle outside this small room halted. Two _Priests_ have already** **fallen-** " She spat the word. **"-and only one beast is wounded. There are quite a few of them, aren't there?** " Her fangs glinted as she smirked. " **I suppose you want me to kill them for you, yes?** "

Claude nodded. "Exactly that. How does this work? I summoned you, so you have to do as I say, right?" Bold words, but she was trapped within the circle, and he had done everything right. 

The feral grin widened. " **Theoretically, yes.** "

The sinking feeling in Claude's belly began to grow. "O-Only theoretically?" His unease only fueled her.

A strange sound rumbled from her chest, and it took Claude a few moments to realize that she was laughing. Her face, outside of her mouth, seemed to keep the same expression, making it hard to distinguish any of her mannerisms. Those hollow, golden eyes were impossible to read. " **I suppose it would have been different if you'd used a lesser circle for a Lesser Demon.** " Her foot stepped forward, outside of the circle. The blood that had been contained inside began to seep out as the ring failed to hold her. She wasn't much taller than he was as she loomed over him, but the sheer _power_ that pulsed off of her in waves... his hand trembled as it reached for a dagger to his side. 

" **Too slow**." 

Her tail lashed out and slapped at the belt, tipping the sheath over to deposit the dagger haphazardly against the floor. It clattered with a sharp sound, and then everything was silent. Claude took a few steps back until he pressed against the wall next to the door. She followed, clawed hand scratching into the wall beside his head.

" **Do not take offense. The likes of you cannot bind me. I am no Lesser construct. I am the Ashen Demon of blood, war, and victory.** " Claude couldn't pinpoint the moment time had started back up, but the crashes and screams from outside did nothing to distract him from the terrifying horned demon that had him backed against the wall. " **I will not kill you, though. You summoned me and have given me a contract-less existence on your plane. I should be thanking you. I will take this battle as your gift to me.** " With every yell or explosion of magic, the aura around her grew. 

The initial panic Claude felt began to ebb. Well, at least he wasn't about to die by the claws of this terrifying demon he'd summoned. If he played his cards right, perhaps he could shoot two birds with one stone. "Any chance we could focus on the beasts instead of the uh, _priests_?"

The Ashen Demon chuckled as she pulled the door off its hinges, power spiking as she readied to enter the battlefield proper. " **Heh. That's cute.** "

 _Think Claude, think!_ He urged, racking his brain for a final scheme, a hail mary strategy to salvage the situation. They had immense firepower on their side now, but how to aim the cannon without holding the fuse? "That's disappointing." 

She paused, tail flicking with an unknown emotion. " **It is inevitable~ I will at least put on a good show for you.** " 

Claude shook his head, stepping forward to stand beside her as the battle raged in front of them. "No, it's disappointing that you're not the true Ashen Demon." 

Her clawed hands balled as she rounded on Claude, snarling. " **There are no imposters!** " 

"Well, _any_ demon can take out some Priests, but can they rise to the challenge of defeating the beasts without harming a single human? Save them for last. You know they'll be attacking you too. The Demon of war would _relish_ the opportunity to thoroughly dismay their opponents by demonstrating just how outclassed they are, yeah? Break their spirit before you break their bones." Claude prayed to the Goddess if she'd even hear him now, that this would work. 

The Demon's eyes watched him, narrowing as she thought to herself. Claude knew better than to keep pushing his luck, she'd let her have all the time she needed if it meant turning this fight around. If what he felt in that room was right, she could take all of these beasts on by herself. _But who will reign her in?_ Questions for another time.

" **...** " She cast one final look at Claude before rumbling angrily. **"Fine. The Priests are last. But don't you dare take your eyes off of me, I want you to experience my prowess first hand and know the folly of your _disappointment_." **The breath that Claude didn't realize he'd been holding deflated out of him, shoulders slumping in relief. The Ashen Demon winked with a sly smirk before jumping forward, running on all fours to slam her horns into the closest demonic beast she happened upon.

**Notes for the Chapter:**

> Thank you so, so much for reading. <3 
> 
> I sincerely hope you enjoy.
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	2. Bound

**Summary for the Chapter:**

> Seteth is faced with a seemingly undefeatable enemy, but there are always loopholes to be exploited. 
> 
> The Ashen Demon becomes bound.

Garreg Mach had been Seteth and Flayn’s home and sanctuary for more years than Seteth could remember. Every fiber of his being ached that this sacred ground was under attack, but every strained fiber was going to be used against these strange beasts that threatened the sanctity of their safety. On his honor as Rhea’s Lead Priest and Flayn’s father, he would defend. His lance speared a flying beast between its eyes, felling the monster immediately. One down, too many to go. “Keep pressing forward!”

“Seteth! _Seteth!_ ” A voice from below, his wyvern screamed for his attention. With a pull of the reigns, his wyvern banked to the left to make a quick landing. 

His eyes scanned the chaos for the source of the yell, sliding down the flank of his battle mount. One of the Knights of Seiros flagged him down, breathless and bloody. The Knights were by the student dormitories. _Goddess, don’t tell me you’ve been pushed back already._ Seteth cleared his throat to rid himself of the worrisome thought. “Speak, how fare the dormitories?”

The knight pointed in the direction he’d come, albeit shakily. “Seteth… there’s… there’s a demon!” 

Seteth bit back irritation and gestured around them. “Are these beasts not all demons?” 

The knight shook his head and reached for Seteth’s shoulder to nudge him. “No, a summoned demon. It’s one of the strongest I've seen. We’re going to need you immediately.” 

_A summoned demon? Were the beasts being controlled by someone who could both lead these abominations_ **and** _summon a demon_? He was beginning to wonder not what but who was orchestrating such an attack. “I will be there right away. Stay here and assist with the straggling monsters.” 

“As you command.” The soldier saluted and joined the ranks of the staff battling the last few flying beasts. 

Seteth boarded his flying beast and clicked his heels. “To the dorms, hurry!”

\-----

The Ashen Demon jerked her head upwards, tossing the creature she’d gored with her horns clear over her shoulders. Blood spattered around her as the beast let out an agonized scream. “ **That is unpleasant. Silence.** ” In one moment, she’d been a few paces away. Claude swore he hadn’t blinked, and yet now she was standing in front of the tossed beast. Her clawed fingers sliced its throat, silencing it with a gurgle before the rest of its body relaxed. Claude pressed his back to the wall when the Demon turned to him. The sight of her claws and horns slick and wet with blood, her tail lashing behind her as she seemingly enjoyed this. It was frightening. 

“ **Hold out your arm.** ”

“Excuse me?”

“ **Hold out your arm.** ” She threw her arm out to the side to demonstrate. Nervously, Claude followed suit. The moment her clawed fingers rose towards him, he instinctively flinched away, causing her to sneer. “ **I already told you I would not injure you, but I will make you useful.** ” Her finger drug a small line across part of his arm. Claude’s stomach churned. _A tally._

The Demon’s chest rumbled with a growl before she turned to join the fight once again. Claude tried to count all of the beasts he could see by the dormitories, curious if she would be the death of all of them. At the rate she was attacking, he wouldn’t be surprised. Whenever a beast fell, he could feel the same sensation he had earlier when time had stopped. When that feeling disappeared, there was another smooth line on his arm. Was she stopping time after each kill to add to her tally? It seemed an irresponsible use of such incredible power, but Claude was not going to voice his opinions on The Ashen Demon’s methods. She was doing great. It was the _after_ that he was most worried about. 

\---

Seteth could feel the Demon’s power before he could see it. It was like a pain in his chest that, while he knew it wasn’t real, made him want to cry out in anguish. _What an immense aura_ … It was going to take an effort to defeat such a summon. Perhaps if he destroyed whoever had her bound? The thought was tempting if it meant he saved both time and lives in the process. Any outsider would stick out, so he could be safe lashing out indiscriminately. As they neared the battlefield where The Ashen Demon fought, his Wyvern began to balk nervously. A shake of the head here, a nervous rumble there… _Goddess protect._

There, the dormitories were within his sight. Seteth had imagined seeing it overrun with the beasts as the other sections of the Monastery were, but he was pleasantly surprised to see battlefield littered with beast corpses. The remaining attacking creatures were engaged in battle a hundred yards away or so. It wasn’t until he saw the Knights of Seiros forming a line to protect students as they healed that he expressed his confusion. Who were the beasts battling? Seteth’s left hand became enveloped in bright white light as he ran towards the remaining creatures.

\---

The last three animals circled her, gaping maws dripping saliva as they waited for the right opportunity to strike. With every slaughtered foe, The Ashen Demon’s power grew. Her aura was threatening to brim over, energy pulsing through her veins as the last remaining enemies. 

Wait.

The spike of holy magic lit up her senses like a radar, causing her to look over her shoulder at the man on approach. Blue robes, green hair… The magic he carried was strong. She wanted to fight him. 

The beasts had other plans. 

The moment she turned in her curiosity, they jumped. Claws, fangs, tails… whatever could be used as a weapon was as the beasts converged on her position. “ **Weak.** ” The Ashen Demon growled, almost in annoyance, as she held her right arm into the air. A sword began to materialize out of the darkness, chunks of bone forming up the length of the strange blade. The display startled the beasts who hesitated for a mere second. 

That second cost them their lives. 

While the sword was forming, the Demon’s tail lashed out to slam into the side of the closest beast’s head. It knocked it to the side, freeing up space in the triangle of destruction for her to slip out. The lunging monsters crashed into each other with guttural growls, heads turning to glare at her with fury. 

The sword was done. It radiated nauseating energy, red pulses ebbing off of the weapon with each swing. The three beasts scrambled backward, afraid. “ **Stand proud and face your deaths with courage, beasts.** ” Smoke poured off the sword as she raised it in a combat stance.

\---

Seteth stood, mouth agape, watching as the Demon took on the remaining beasts. Thousands of questions rattled through his brain. _Why is she attacking the Demons? Who is commanding her? What is this power?_ She was no Lesser Demon, that was for sure. Perhaps a General? The commanding air around her, the sheer _presence_ … it wasn’t unlikely. Still, the monstrous tail not unlike his Wyverns, thick horns that jutted backward while another pair curled around like a ram, the feral claws at the ends of her fingers. She was bred for battle, and Seteth was the only person in the Monastery that could rival such power. Rhea, Goddess heal her, was incapable of such a feat at the moment. Steeling his resolve, Seteth lifted the hand cloaked in magic forward, aiming to send a blast of energy at her back. The world seemed to grow silent as the beast scampering away from the Demon halted. Time itself seemed to have stopped for all but Seteth. Such a phenomenon would have been fortuitous in slaying all four monsters before him at once if his magic worked. Instead, he felt no power come to his aid. 

The Demon turned to look at him over her shoulder, sending a chill up Seteth’s spine.

“ **I knew you’d be interesting.** **Tell me, where have I been summoned? These beasts are no mere coincidence.”** She turned to face him fully, crossing her bloodied arms. 

Seteth narrowed his eyes, leering. “I do not see how conversing with you is pertinent in any way, shape, or form, foul Demon.” Demons were known for their power and trickery, sharp tongues almost as potent a weapon as their magics. He needed to be careful; a dangerous game was afoot. 

“ **I’m afraid that’s not a very satisfying answer. How about we try this again?** ” The Demon’s hand rose as magic pooled in her palm. Seteth braced for impact, but her hand moved to direct itself at a frozen Claude, covered from head to toe in small red marks. Rage bubbled within Seteth as the Demon grinned at him, fangs glinting in the torchlight of battle. The only emotion that bubbled off of her was the need for victory. “ **Are you** **_properly motivated_ ** **now?** ” 

“Abomination.” Seteth snarled, hands balling into tight fists. He charged forward, aiming a blow for her jaw. If she faked to the left or right, his left hand was prepared to follow up. Even if it were just his fists, he’d tear himself apart against her if it meant his home was saved. 

Much to his surprise, his fist connected with her jaw. However, she did not budge. Only her chin tilted up with force. The position gave her an excellent opportunity to smirk down at him through half-lidded eyes. “ **Claude was right. It is much more fun to let an opponent know how outclassed they are before putting them into their place. You know.. I wouldn’t mind putting** ** _you_** **in your place.** ” A claw trailed up the front of his chest as her chest purred a strange, foreign sound. He staggered back as if struck.  
  
“How dare you speak my student’s name with your filt-” He paused, eyebrows scrunched with confusion. “How… how do you know his name?” Tired, worried eyes turned back to the frozen leader of the Golden Deer. 

The Ashen Demon chuckled, though the mirth did not reach her features. No emotion seemed to. “ **Your little pupil summoned me, of course.** ” 

“LIAR!” 

“ **He had help. The chalk did not smell of him. However, they had the best of intentions at heart when they offered me his blood, so don’t worry.** ” As much as Seteth wanted to believe she was lying, something told him she wasn’t. If Claude summoned her, did that make the young boy her master? If she was on their side, then his worries could be put to rest until they figured out a way to send her back to the pits of hell where she belonged. 

He cleared his throat and crossed his arms. “Is that why you are battling against the beasts with us? Was that Claude’s command?” _Goddess help him, that better have been his command._

The Demon crossed her arms as well, Claude no longer in immediate danger. Seteth allowed his shoulders to relax the slightest millimeter. “ **I have answered one of your questions. Perhaps you answer one of mine?** ” She suggested, the tip of her tail flicking with annoyance. There was a slight strain to her voice, no doubt from keeping time frozen for so long. Still… it was terrifying such a power existed. 

As much as Seteth wished to rush the Demon in front of him, perhaps playing along with her questions would help weaken her as time was stopped. 

“Very well. You are in Garreg Mach Monastery, in Fodlan. We know not where the beasts are being sent from, only that they’ve been waiting and gaining in number outside the walls until they attacked tonight.” 

“ **There, was that so hard?** ”

“Yes.”

“ **Such spirit…~** ” She purred chuckling. “ **Very well. Yes, that is what Claude wished for me to do. However, I am unbound. The Ashen Demon lives as she pleases, seeking only the most chaotic of battles to win.** ” Her tail swished slowly behind her as she searched Seteth for his reaction to such news. 

An unbound Demon…

“ **I am going to let time begin again. These three beasts will attempt to fight once again, but I will dispose of them quickly. I only agreed not to attack humans until all the beasts were slain-** ” She noticed the look of anger cross Seteth’s face. “- **but do not worry. I will save my first dance for you.** ” 

“Damn you-” 

Time began again. 

\---

The Ashen Demon released her hold on time, cursing to herself. She’d been too careless, too drunk on the power of being _unbound and free_. The magic required to stop such a wide radius was immense, and she wouldn’t be capable until she rested. Still, no one seemed to be stronger than the Priest before her, so as long as she took care of him, freedom was secure. First, the beasts, then the priest.

True to their nature, the beasts recollected themselves and surged forward, jaws snapping for any purchase in the battle. They were aimless, though. Blind bulls, merely charging at the first red flag they came across, never destined to run outside of their ring. The sword in her hand seemed to dance in her hand as she sliced horizontally in their direction. They were still a slight distance off, nowhere near the blade. 

They didn’t need to be. The sword broke into multiple pieces, bones rattling as the weapon elongated. Each sharp shard hungered for blood as all three beasts were sliced. Upon impact with the sword, they fell to the ground. 

Claude and Seteth watched, stunned. The young man waited for time to stop, waiting for the feel of her fingers as they traced his skin, but nothing happened. 

“P… Professor! _Professor! She didn’t stop time!_ ” Claude screamed. “ _I don’t think she can do it again!_ ” 

\---

Seteth’s magic flared around him at Claude’s words. His hunches were right; she’d spent too much time with him while time was stopped. If he were unsure, the furious glare The Ashen Demon threw at Claude was enough. 

“Unbound or not, you will still bleed!” The Priest snarled, charging. The Demon was unbothered as she jumped backward, sword at the ready. 

“ **Don’t tempt me with a good time. I am The Ashen Demon, the embodiment of victory and war. Blood is in my nature**.”

Seteth did not entertain any further banter, magic shooting from his palm towards the last thorn in his side for the evening. Exhaustion weighed him down as they danced on the battlefield, graceful movements indicative of skilled fighters. For every parry Seteth had, the Demon had a dodge. Every strike was followed by one on the other. Were the circumstances different, Seteth would’ve possibly enjoyed the challenge. Too many lives were at stake, though. It was a morbid path of thinking that only led to destruction. 

This battle, though… it was going nowhere. They were evenly matched, but the Demon before him was a wildcard. How long could she keep this up? How many more hits could she take? Seteth felt himself begin to slow. Mistakes here and there, less force within his blows. He knew she could tell, as well. Her attacks were becoming more feral, more unhinged. Her tactics were predictable now, but he lacked the strength to take advantage of it. 

How it angered him. 

How he wanted to pierce where her heart should have been with his spear, securing victory not only for Garreg Mach but for the Goddess as well. Her existence was against everything he stood for. 

But he could not kill her. 

\---

 _Why won’t this mortal fall?!_ The Ashen Demon protested in her mind, muscles taut and shaking with the exertion. If only this man had been her first opponent, how would things be different! She relished a challenge, but the _victory_ was the real prize, and she _would_ have it. 

“ **Enough of these games** .” She snarled, catching the neck of his spear with her clawed hand. Blood began to trickle down the haft. “ **You are skilled and have earned your warrior’s death.”** With the last surge of her magic, she managed to wrench the lance from his hands and toss it behind her. Her tail slammed against his side, causing him to stumble. Off on the sidelines, a woman screamed. 

_Delicious_. 

Seteth stumbled to the side, losing his footing as he fell onto his back. The Demon was atop him in an instant, hands holding his own above his head. She straddled him, the weight of her tail keeping his legs still. He was utterly at her mercy in such a compromising position. 

She could hear the footsteps across the courtyard as people began to charge toward them. Despite it all, she leaned down until her head was close enough to whisper in his ear. He struggled against her, jerking his head to the side and away from her. 

“ **I don’t need to stop time to relish this moment.** ” She purred. Seteth tried to kick his legs and move his arms. The pressure on his limbs increased. “ **You fought well, but this ends now.** ” 

“I agree.” He hissed, the last of his magic enveloping his entire body. Instead of the white magic she’d been used to seeing, it was gold and green. “However, this will not be a satisfying conclusion for you, Ashen filth.” 

He lurched forward with his head, slamming his skull into her face. He knew it wouldn’t get her off of him, but if he applied similar force as earlier, she’d let up just enough-

 _There!_ His right hand slipped out from under hers. A sigil flared in his palm as he slammed it into her chest, yelling with desperation the entire time. The Ashen Demon let out a furious roar as her tail lashed in pain. “If I cannot kill you-”  
  
“ **No! NO!** ” She pawed at her throat as something began to form, the bright sigil shining through her chest and back. Those that were running towards them stopped in shock at such a display, unsure if it was safe to approach.

Seteth relished the shock on her face. Perhaps she was capable of emotion. “- then I will bind you to me so that you cannot harm a single living thing here.” 

The weight of his words was a knife slipped through her ribs. It couldn't be! “ **Damnit! You bastard-** ” A thick, golden medallion connected to a collar formed around her neck, thudding against her chest where Seteth had struck her. It bounced against his hand, the iron cold and heavy. The sigil remained burned into her flesh even after his hand fell away.

The Ashen Demon scrambled off of Seteth, desperately tugging at the shackle that bound her. Pain from the sigil burned to her very _core_ , but it was not as hot and sharp as the sting of _loss._ It shouldn’t count. He couldn’t kill her, and she’d killed what seemed like hundreds of beasts!

And yet, it didn’t matter. 

She was bound. 

Seteth’s head fell back onto the soft grass as his eyes closed, too exhausted to keep conscious. The Ashen Demon stumbled, falling to her knees as the weight of her captivity all but crushed her. The last thing she remembered was watching a crowd of students flock around Seteth, and the shining armor of the Knights as they approached her. Her eyes focused on Seteth's peaceful face as conscious slipped from her grasp.  
  
“ **Damn… you.** ”

**Notes for the Chapter:**

> Thank you so much for reading <3 
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	3. Byleth

**Summary for the Chapter:**

> The stipulations of the contract are discussed, and The Ashen Demon reveals her human name.

The wall had suffered substantial damage and would probably take months to rebuild correctly. Due to the danger a gaping hole in the Monastery wall posed, the Knights of Seiros took turns cycling out guard duty to avoid another evening of battle like the one they’d had last night. Casualties were at a minimum due to The Ashen Demon’s interference, the only loss of life stemming from a few members of staff. They knew the dangers going into the night, and there was no doubt that the Goddess would watch over them eternally. As far as injuries go, there were no wounds that couldn’t be healed by white magic. 

Save for the Demon’s, of course. 

When The Ashen Demon came to, the world seemed _wrong_. What was this feeling? Such weight, the burden of responsibility pressed heavily on her chest. Where was she? Her eyes tried to survey the area around her without moving her head, careful not to alert anyone around her that she was awake. The interior of a bedroom, perhaps? She had expected a cell, a prison with as many locks as possible. It took everything in her power not to be insulted. She was a conduit of rage and energy, haphazardly dropped to the _floor?_ When her curiosity couldn’t be sated any further, she lifted off the floor to sit up. 

Seteth was being tended to by a white mage as he lay resting on a bed, the glow of their magic gently healing his wounds. His eyes were closed, and he still wore that look of peace he did when he’d lost consciousness after their battle. 

After he’d bound her, the bastard.

She hoped his wounds healed stiff.

The memory hurt more than the wounds she’d taken, granted _hers_ would have to heal on their own. The man in his bed probably felt smug with his little plan, but here he was defenseless. 

They were all defenseless. 

As she silently plotted, her tail thudded against the ground. The mage jumped, startled at the sudden sound. “Worry not, Mercedes…” Seteth’s voice sounded tired as he opened his eyes a bit. He looked about how The Ashen Demon felt, though she’d never honestly admitted it. “She cannot harm you.” 

“I know, it’s just… I was startled. I’m sorry.” Her voice was soft and jarring to the Demon’s ears, causing them to flick back in annoyance. Mercedes glanced at her once again, fearful of the dried blood on her horns. She quickly returned to her work.

“ **How can you be so sure of that, Priest?** ” The Demon growled, wincing as she lifted her arm to check a cut. Mercedes did her best to ignore her, magic faltering ever-so-slightly. 

Seteth slowly rose as well, scooting back to lean his back against the headboard of the bed. “Thank you, Mercedes. That will be all for now. I will attend to the rest of my injuries.” The young woman looked as though she might protest, but after another glance at The Ashen Demon, she nodded and disappeared out the door without another word. At least a little amusement could be gleaned from the morning; the girl was terrified. 

There was another spike of white magic as Seteth began to heal the rest of his wounds, seemingly ignoring The Demon altogether. She visibly bristled, eyes narrowing. Perhaps if she worded it differently? “ **You are incredulously nonchalant for an injured man alone with a Demon.** ”

“I acknowledged your question the first time, demonic filth. Rewording your inquiry will not change the outcome.” Seteth’s cold stare avoided her altogether, his focus solely on mending the wounds she’d inflicted on him. The hairs on the back of her neck rose as a growl rumbled in her throat. Her body moved before she could think, quickly jumping onto the bed to be eye to eye with the Priest. 

She was poised over Seteth as he healed himself, eyes boring into his while her limbs sat on either side of him. Her tail lashed from side to side, causing the bed to creak occasionally. There was no hint of coy sensuality like on the battlefield, the feeling of two rivals sparring until one held a sword at the other's throat. No, The Ashen Demon was angry and demanded answers. 

“ **What did you do to me?** ” Her clawed hand pulled her loose shirt to the side, revealing the bright gold sigil seared into her flesh. 

The proximity seemed to bother Seteth, though to what degree the Demon could not tell. The tips of his elongated ears twitched slightly as he chose his words carefully. “I bound you with my patron’s sigil, the Crest of Cichol.” _Cichol… Cichol… she’d heard the name before. But when?_ “I request that you remove yourself from such a close proxi-”

“ **Make me.** ” She growled, tail lashing as she crouched in front of him. Everything in her body dared him to strike her, fight back, anything to acknowledge her. 

The attempt at tension was not lost on Seteth, though he made no move to entertain such folly. “Fine. _Move._ ” Something about his tone gripped at her chest, heavy and hot. The pain started small, like an annoying splinter. The longer she remained still, defiantly snarling in his face against his wishes, the pain grew. It wasn’t until it felt like a hot iron being pressed against her chest where the seal had been placed that she wrenched herself off of the bed, crouched ferally as a clawed hand rose to check on her chest. No blood. Was it-

Yes. She’d forgotten this feeling before. 

“Do you now understand why you cannot harm anyone here? It is the will of the one who holds your reigns.” Seteth was not smug about the fact, almost sad as he glanced over at her. “My soul is now permanently stained by your intermingling with it, but it had to be done. Tell me, do you feel the stipulations I put into our contract?” 

If she concentrated hard enough, she could. It had been thousands of years since she’d been contracted, so it was almost like remembering to do a task you’d only have done in your childhood. “ **I am not to harm any of the souls within the Monastery here.** **I must assist you with an illness. I am only released from my duties when you see fit, or when the sigil fails. Any slight transgression against commands results in pain, and any transgression against the stipulations of the contract results in immediate death.** ” 

Pleased, Seteth nodded. “Yes, this is corre-” 

“ **But tell me, can you feel my contract?** ” The Demon interrupted, sitting down on the rug across the room. The mild irritation Seteth felt was immediately replaced with prickling unease. 

“Your... contract? I am afraid I do not understand.” 

The Ashen Demon's tail curled forward into her lap so she could run her fingers over the scales. “ **Lesser Demons can be called to your plane for your bidding, but I am a Greater Demon. I believe the clergy call us Generals. We come at a price. You have your stipulations, but tell me, Priest, what is it I require of you?** ” Her gaze rose from her scales to watch him as he squirmed. 

The green and gold sigil on her chest, The Crest of Cichol, began to shine on her chest as Seteth explored their bond. Horror crept across his face, and his hand lowered to his shirt. Shaking fingers pulled the laces loose so he could pull the shirt’s low neck to the side. A black and red sigil pulsed in the same spot he’d placed one on her. The lines crossed each other and a tangled weave, symmetrical in its design. When his fingers brushed against it, she could _feel_ it. 

“You require battle, to cause carnage on a battlefield at least once a moon. You require blood-” The implications of such a requirement made him pale, but as he closed his eyes and concentrated his shoulders relaxed. “-thankfully, it is metaphorical. Prey, meat, hearts will do. And you require a significant victory every moon. How is this determined?”

The Ashen Demon shrugged. “ **I do not pretend to know how the more...** **_mystical_** **aspects of contracts. I suppose we’ll have to find out, won’t we? I’m sure I’ll keep you informed if I’m not adequately satisfied.** ” 

“Yes… I suppose you will.” The premise did not thrill Seteth in the slightest, nor with her word choices, and The Ashen Demon did not need any mystical bond to tell. If she were genuinely bound to this man, then it would be her job to make it as strenuous as possible for him. Whatever it took to break the contract, starting with whatever weaknesses she could find. 

Seteth stood and moved to a wardrobe, preparing to get dressed for the day. The Ashen Demon couldn’t help but be jealous at how easily he moved now that he’d been healed. She felt no shame as she watched him, studying him from head to toe. He had the body of a fighter, muscles tight from years of hard work. Why was he a tome thumper? His legs were strong, used to gripping a Wyvern amid battle. Her mind thought of a few things a talent like that could come in handy for, but she was not allowed to be close to him right now while the command was still fresh. 

Now acutely aware of her eyes on him as he planned to undress, Seteth’s ears reddened as he glowered at her, turning away so that he did not face her. “ _Turn around._ I will not permit such lecherous staring, creature.” The weight of the command flared to life in Cichol’s crest on her chest, starting the timer. Even as she felt a slow pain began to rise, it was more about proving a point. 

He slipped his shirt off, tossing it gently into a small bin for clothes. His back muscles rippled with each movement, and it was all The Ashen Demon could do not to imagine her claws raking down them, exploring the topography with nothing but her fingertips. “ **I have a name, you know.** ” She mused, attempting to swallow through the pain that continued to rise in her chest to further enjoy the show. 

“Yes, yes, The Ashen Demon, so you’ve mentioned.” He hooked a thumb in his waistband and began to slide out of his pants before he stopped, only the top of his smallclothes peeking out above the pants. Suspicious, Seteth glanced over his shoulder to make sure that the Demon was not watching. Anticipating the gesture, her tail rose to cover her eyes, but she couldn’t resist wiggling her fingers in a slight wave.

Though she couldn’t currently see it, hearing Seteth’s scoff from across the room made the terrible day a little better. The nagging pain in her chest was getting to be too much, but she’d have plenty of days to continue to show, so she complied, turning wholly around. He could only hide behind these feeble commands for so long. The Demon would only grow more powerful as she fought against him. It was in her nature. “ **No, I have a name more appropriate for your tongues.** **Tell me yours, and I will tell you mine.** ” 

Seteth considered this, buttoning his robes and straightening out the sleeves. After a few careful minutes, he sighed. “I suppose it could do no further harm. I am Seteth.” _Seteth… hmm._ Interesting.

“ **I am Byleth**.” 

**Notes for the Chapter:**

> She's branded with the Crest of Cichol, and he is branded by the Crest of Flames
> 
> also obligatory exposition chapter before shenanigans begin
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	4. Uneven

**Summary for the Chapter:**

> Byleth, The Ashen Demon, works to press all of Seteth's buttons to try his patience. His displeasure grows throughout the day as he's forced to utilize commands to keep Byleth in check. 
> 
> Until, of course, he snaps.

The warm waters of the bath soothed Byleth's aching muscles as she lounged in the tub, tail slipping over the side to hang in relaxation. A bit of water pooled on the floor as it dripped, but she was sure someone would clean it up. It was, quite honestly, relatively close to the bottom of her priority list. Seteth couldn't watch her every minute of the day with how stressful his job was, whatever it was, so he had assigned someone to accompany her as if a chaperone would deter her from evil behavior. They could handle a bit of clean-up duty. 

What did he think she was, an _imp_? She was not here to tie shoestrings together under tables and spit into water wells. Humans had a skewed view of how demons operate. If he genuinely had half a mind, he'd command her to teach him everything she knew about demons. Weaknesses, strengths, hierarchy… but she was sure he didn’t trust a word out of her mouth. Despite sharing her human name, he'd yet to call her by it. She didn't mind; his approval was not something she needed in her life. 

Her rough thumb brushed over the crest on her chest, wondering if he felt when she touched it, as he did with her. Her hand tried to will a bit of magic to heal a gash beside it, but she was tapped. _Oh well, it was worth a shot_. Nothing in this Monastery would attack her if they knew what was good for them, so she wasn't worried about suffering another loss. Tomorrow these aches would be the least of her worries, and she could focus on more important things, like getting out of the contract.

The steaming water of her bath soon lost its bite, becoming chilled with time. It was no longer enjoyable, so she stepped out and caught her reflection in the mirror across the room. 

Byleth, The Ashen Demon, was a pure killing machine. Hard muscles boasted years of use, faded scars dotting the landscape of her skin to document close calls or valiant opponents. Two sets of horns: one that jutted backward like a wyvern, the other that curved in like a ram. Claws at the ends of her fingers, made for slashing and gutting foes. A thick, scaled tail for defense and extra utility on the battlefield. Bright eyes to see within the most impenetrable of darkness. Her eyes lingered over the bright green and gold sigil on her chest, the one blemish on an otherwise flawless canvas. “Hmph.” She snorted, turning away from the mirror. “Well, I guess nothing is _completely_ perfect, hmm?” 

\---

When she exited the bathhouse, skin fresh and horns cleaned, Claude was waiting outside for her. Since he had been the one to summon her, Seteth took it upon himself to assign Claude the majority of Demon-watch. The thought had terrified the man, but it was what it was. He tried to think of it more as an opportunity to get information and get on the Demon’s right side, rather than as a punishment for the ultimate blasphemy. “ **Are you my babysitter today**?” Her voice was dry, unamused. 

Claude nodded. “If you want to call it that. Say, your horns are looking better after getting cleaned up. Is your uh-” He pointed a finger to his chest. “- doing any better?” 

“ **No, but your attempts at sucking up and flattery are acknowledged.** ” Byleth’s ears flicked backward in annoyance, much like a cat pestered too long. “ **Tell me, what am I supposed to do when I am not being used?** ” The question seemed to catch Claude off guard. 

“You know? I’m not entirely sure. I mean, _I_ have to go to class. Seteth’s teaching-”  
  
“ **I will accompany you.** ” 

Something about the way the tip of her tail flicked gave Claude a lousy feeling. That answer had been given entirely too quickly. “On second thought…” 

Byleth stopped, looking over her shoulder at Claude with indifferent disinterest. “ **Fine, then I will go on my own. If I am to wither away from boredom, I might as well do it in the most distracting way possible to interrupt whatever the Priest is doing.** ” 

_Goddess, Seteth is going to kill me twice._ “That sounds… _wonderful_. Shall we?” 

While he refrained from holding out his arm to escort the incredibly terrifying Demon that passively commanded everyone’s attention, it wasn’t every day a _literal fucking demon_ was walking around a religious Monastery. “So, Ash. Does it hurt to be here? Like, in the Monastery? Consecrated ground and all that…” Would she grow hooves so that it wouldn’t hurt, or what that even matter? It was beginning to dawn on Claude that they genuinely didn’t know much about Demons. 

The question didn’t seem to offend Byleth in the slightest, nor the shortening of her title. She looked down at her bare feet before trailing her gaze off towards the East. “ **No, because your consecrated ground is disrupted. The Monastery’s perimeter is breached. I assume it will be difficult to exist once the wall is fixed. One would assume after it's remedied that an** **_alternate_** **arrangement can be made.** ” 

“Lovely. You know, you have quite the knack for positive conversation. I bet Seteth is thrilled to have his mortal existence interlocked with yours.” 

The Demon cracked a smirk, amused. “ **The Priest is less than thrilled. Perhaps if he had your sense of humor, it would not be such an infuriating arrangement.** "

As they walked through what was usually a busy garden, Claude caught glimpses of people as they disappeared behind pillars or into separate rooms. He didn't blame them. "When's the uh, last time you were summoned? Like, how long do they typically last?" He'd done as much research as he could before attempting to summon _something_ to help him, but it was hard when all they were working off of was books that he and Dimitri had managed to purchase under the table. 

" **Am I not enough?** " She mused, watching Claude squirm with nervousness.

"Nonono- I mean, yes, but I just-" he ran a hand through his hair in a rare flustered moment. "None of this is taught. I admit I know next to nothing about Demons besides 'Demon bad.'" 

" **You may relax. I was amusing myself. Usually, when Summoned, it is for a particular reason. For you, it was to defeat the beasts in that battle and to assist with the illness. Once the illness was cleared up, I would have disappeared.** "

"But you were too powerful for the seal."

" **Yes.** " 

Claude scratched at his chin in thought. "Okay, but how does a Demon get chosen to be Summoned?" 

Byleth was silent for a moment as they walked, relying on Claude's direction to not get lost in what felt like an internal maze of stone and piety. " **Uses. I was the best fit for the job, though I am curious myself why I was chosen when any other demon could've helped you dispatch the beasts. The closer your core three are to the task needed, the better chance you have of being Summoned, but I am not known for my healing, so it's rather curious."** Her clawed hand gestures to herself in response, wounds from the prior battle still evident. " **I will have a better idea once I can see whoever is inflicted.** "

A bark of laughter escaped Claude's lips as a knee jerk reaction. "Hah! Good luck. I doubt Seteth will let you near her." A bit of the entertainment he'd mustered faded when Byleth purred. Her tail flicked again, gears turning in her head as she processed the possibilities. 

" **Her? Well, this narrows part of it down, at least.** "

 _Damnit, Claude. Seteth's going to kill you three times now._ "We should get to class now." 

\---

Seteth sat at the front of the lecture hall, books stacked on the desk in front of him. Combing through the last of the medical texts they had in the library would have to wait. As much as the tired Priest wanted to focus all of his efforts on cracking Rhea's mysterious illness, they _did_ have classes to teach. If he neglected his duty to the students here, then The Archbishop would never forgive him.

If she ever woke up. 

The remaining students began to straggle in, taking their seats and preparing for whatever Seteth was about to teach.

Well, most of them. 

The light that streamed through the doorway of the lecture hall itself blotted out momentarily, an eerie shadow cast across the stone-grey room. The dominant figure of The Ashen Demon stepped inside, bare feet hardly making a sound as she settled into a seat in the back the scales on her tail rattled against the pavement as she leaned back in the chair, kicking her feet up. A tense hush fell over the students as eyes flicked back and forth between Seteth and Byleth, almost expectantly. 

Seteth knew better than to fight Byleth in front of the students. Given her specialties, if the Priest were trying to put it lightly, the demon would probably enjoy the challenge and only balk when Seteth ordered her. "Golden Deer, our class will have a guest listener today. This is The Ashen Demon. She will not harm you, but be on your guard nonetheless. The Goddess protects-"

Byleth scoffed. 

"-But you must always stay vigilant. It is never enough to rely on the Goddess's protection; you may save your own lives by remaining pious _and_ aware in any situation." The Golden Deer students turned to look at Byleth, who waved her tail lazily I'm greeting. "Do not think our _temporary_ visitor to the Monastery is an adequate reason not to pay attention to the lecture. Turn to page 53 for our lecture on-" seteth checked the notes and gritted his teeth. "Demons." 

" **Oh, how charming. I'm all ears.** " Byleth all but purred, earrings clinking together as the ears flicked out eagerly. It took everything in Seteth's power to ignore her. 

"Now, as you remember from last week's lecture and surprise exam on Demon deterrents-” Seteth paused, wishing he had some of the physical deterrents here to get Byleth out of the lecture hall. “-Demons have a strict code on how they typically behave. There are predictable elements to their behaviors. For example, holy water will melt flesh down to their corrupted souls, and a purifying flame will sear their flesh through any defenses they may have.” 

He closed his book and leaned against the desk at the front of the hall. “But there are more frequent, or predictable, behaviors of Demons that can be exploited. There are always three facets to a demonic entity. For example, our _esteemed_ guest is a Demon of Blood, War, and Victory.” When Byleth was mentioned, she jolted forward as if she’d been woken up. The class struggled to stifle a few snickers as Seteth’s grip tightened on the desk behind him.

“Settle down. So, if we are facing a Demon of War, Blood, and Victory on the battlefield, what is something we can expect from said traits? Ignatz?” Seteth’s eyes darted to a timid looking boy a few desks away from Byleth. 

The boy’s eyes widened when he was addressed. “Um… an aggressive fighting style?” 

Seteth nodded. “Yes, indeed. What else? Hilda?” 

A pink-haired girl -who seemed to share the same amount of enthusiasm being in lecture as Byleth did- tapped her chin thoughtfully. “What about an army?” 

This time Seteth shook his head. “No, I am afraid not, Hilda. One of the benevolent gifts the Goddess has given us is the assurance that Demons can only come to our plane when Summoned, and it is at a one at a time basis-”  
  
“ **Lies.** ” Byleth’s face was hard, emotionless. Claude could have heard a pin drop in the thick, tense silence. The students hardly breathed as Seteth stared down the Demon. He seemed troubled, whether it was that the information he was teaching was false, or that Byleth was here all together. 

“Do you find it necessary to continue to interrupt this lecture?” He was trying his best to keep his composure, but the faintest clench of his hand gave him away once again.  
  
Claude watched with horror from the spot beside Byleth. _Don’t do it, Ash. Don’t… Don’t do it, Seteth is going to-_ “ **Yes.** ” _Aaaaaaand she did it._

Seteth pushed up off of the desk and began walking towards Byleth and the exit. “Forgive me, class. I am going to escort our guest somewhere so that we may continue our lecture without interruption. Claude, you are in charge until I return. Do not make me regret that decision when I return.” Something about his tone set with Claude the wrong way. There was no danger of a prank or any shenanigans at the current moment; he’d be a perfect little demon-summoning angel. 

“ **Guess I’m off to be punished. Farewell, children.** ” Byleth chuckled, standing up lazily to follow Seteth out. Her tail swished back and forth with wide arcs, highly pleased with herself. As soon as she rounded the corner outside of the lecture hall, Seteth shoved her against the nearest stone arch. Her stomach fluttered with the sudden gesture, caught off guard as her horns scraped the stone. It forced her head into a weird angle as Seteth glowered at her. “ **Oh my, this is rather forward, Priest. Perhaps I got under your skin in a different way than intended?** ” 

“Silence, you.” He growled, the tips of his ears reddening slightly. As straight-forward a man as he seemed, flustering him was probably incredibly easy. _Saving that for later, I guess._ She mused as Seteth continued. “We do important work within the Monastery, and I will _not_ have you making a mockery of our teachings!”

“ **Then, don’t teach false information.”** Her reply was smooth, even. Everything Seteth didn’t feel right now. 

“I _command_ you to refrain from negatively interfering with further lectures.” The brands on their chests illuminated with their respective lights before they faded underneath their clothes. Byleth’s gaze had hardened.  
  
She spat to the side, angrily. “ **You are lucky you can continue to hide behind these commands. Is that how you get through life, commanding those who have no choice but to obey you? At least those I commanded did so out of respect.** ” 

Seteth shoved a bit harder, Byleth’s horns scraping once again. “Demons know nothing of respect. _Follow_.” The lights that connected them flashed once again. The Ashen Demon rolled her eyes in frustration, tail lashing angrily from side to side once Seteth stepped back and began walking. They both steamed angrily, riled up by the other, whether it was intentional or not. “I am going to take you to the Training Grounds, where I will put you under the command of Felix. Listen to what he says. I believe you will be better suited to spend your time here when I cannot keep an eye on you.” 

“ **Whatever gets me out of your hair, yes? Displace the problems you cannot control onto others?** ” A low growl rumbled in her throat. “ **You are a poor leader. You must tackle every problem head-on until you’ve gained control over the situation, the troop’s respect follows shortly after. Instead, your students see you squirm and turn tail from issues you cannot think to overcome on the spot.** ” 

_"That is enough_.” Seteth whirled around to stare at the beast behind him angrily, eyes boring into hers with fiery intensity. In any other circumstances, it might’ve been attractive to the Demon. Who didn’t mind being put into their place every once and a while? There was no command behind the words, but Seteth’s anger seemed to leave no room for discussion. 

“ **Fine. Take me to Felix.** ” 

\---

The Training Grounds were not far from the lecture halls, a completely sectioned off area set for combat maneuvers and drill practice. Byleth had expected the sharp sounds of steel tang against tang but was instead met with dull echoes of training weapons. Of course, though. This section of the Monastery was a place of combat _learning_ , not a trial, much to her distaste. 

“Felix!” Seteth’s commanding voice halted the few individuals on the grounds, all faces turning to the man. Felix did as well, a tall, lithe swordsman who had been locked in combat with two other students. “Felix, I am entrusting our… _guest_ to you for the next few hours. She will not hurt you, but the lecture hall is no place for her interruptions.” 

Byleth felt his eyes look her up and down, appraising her skill at a glance. He eventually spoke. “Of course, Seteth.” 

“Thank you. I will return after the remaining lectures of the day. Catherine is here as well if you need assistance.” The Priest dipped his head before turning on a heel, eager to get away from Byleth and her irritating intentions. Once he was out of sight, Byleth rolled her eyes and crossed her arms. 

“ **So, you are Felix? I’ve heard a rumor you know how to put one of those to good use.** ” Her tail flicked nonchalantly towards the training blade in his hand. 

The praise made the boy stand straighter, though he played it off as a stretch. “Strength is the greatest measure of an individual. I take great pride in my abilities. I’ve heard a rumor you are a beast of battle. Cross swords with me, I’ll measure your worth.” 

_Perhaps Seteth was on to something._ She thought to herself, stretching her arms above her head. “ **Very well. I will not use a weapon, though. There would be severe repercussions if I were to injure you.** ” 

Felix scoffed. “We'll see, the only one here that gives me a good fight is the boar prince, but that is enough talk. I find out more about someone from this anyway.” He dropped into a fighting stance, blade held firmly in front of him. The solidity of his position brought a smirk to Byleth’s lips. At least he knew what he was doing.

“ **Agreed. This will be far more interesting than sitting in that lecture hall listening to the Priest sling nonsense.** ” 

\---

Felix landed on his back, head thudding against the cobblestone with a grunt as Byleth stood over him. His training sword had been batted away, useless a few paces away from their fight. Entirely and utterly defeated, all he could do was sit and gaze up at the monstrosity above him with wide eyes. As much as it pained him to admit it-

“You win.” He growled, pushing away the tail that hovered just inches above his neck, rather than a weapon. Quickly he clamored to his feet, running a hand through his hair to set it back into place. “Having an extra appendage aids you in combat. I didn’t realize you could use it for defense as well, how hard are those scales?”

Had it been Seteth, would he have accepted defeat so readily? 

“ **Hard as steel. It’s as good as any shield, though it is limited in use since it is attached.** ” 

“I see.” He rumbled, rubbing a sore spot on his elbow from where he’d fallen. “My sword maneuvers usually cover my open spots, but with the addition of a tail for battering, I was played like a fiddle.” 

“ **Excellent assessment. Many of my kind have extra appendages of a sort, be it arms or tails. I see you fight well against humans, though.”**

The human didn't seem satisfied with the praise this time, steely gaze already attempting to appraise her for the next clash. “It only does me well if I am fighting humans, though. If I am to cross blades with Demons in the future, I need to win.” 

Byleth looked him up and down once again. Well, Seteth couldn’t disapprove if she did something helpful, and it just so happened to be something interesting. Two birds, one stone. “ **Very well. Keep your elbows down, and…** ” 

\---

“Thank you for your attention. This lecture has concluded.” Seteth lowered the book in his hand and placed it gently on the desk before him. The Black Eagle class all but jumped on the opportunity to leave a few minutes earlier, thanking Seteth with rushed appreciation. Usually, he’d have taken this time to spend with Flayn and on his studies with Rhea’s condition, but there was another matter at hand. 

_Ugh…_ Seteth ran a hand through his hair and straightened the circlet on his forehead in a mirror. If he was to go put out fires that Byleth had inevitably started, he could do it without looking as frazzled as he felt. Satisfied with his appearance, the man took one last deep breath before exiting the classroom. 

Seteth had dropped her off with Felix at the Training Ground. He did not doubt Felix’s ability in battle, or to keep Byleth’s attention as she assessed him as a fighter. No, Seteth's complete and total doubt was in Byleth’s ability to stay out of trouble long enough for him to finish what he needed to do. The sooner he cured Rhea’s illness, the sooner he could send The Ashen beast back where she’d come. Still, it was surprising not to have Cyril or another flustered student knocking down the lecture door with terrible news. 

“Excuse me-” A student ran past Seteth, clutching training gear as he rocketed down the stone hallways towards the Training Grounds. The sight brought a rare smile to Seteth’s face. Such unabashed enthusiasm in training and bettering one’s self? It was everything they’d hoped to accomplish when Garreg Mach opened its doors as a school. 

“Oh! Pardon me, Professor Seteth!” Another student rushed past him, heading in the same direction. Seteth squinted suspiciously as they too disappeared around the corner. What was going on at the Training Grounds? Perhaps his pleasant surprise was premature - The Ashen beast was up to something. 

His pace quickened, rounding the corner to what seemed like a long line leading to the sparring grounds themselves. He shoved past a few students who were watching two dueling figures eagerly. In the center of everyone's attention, Byleth and Felix locked in another spar. The students buzzed amongst themselves, eager for a turn with Byleth. Her hands were behind her back, clasped tightly together as she avoided using them. The training sword rattled against her horns as she deflected blows, careful to cover her blind spots. Whenever Felix attempted to take advantage of the open places made by her lack of arms, her tail would whip in the way and deflect. 

Byleth was hardly breaking a sweat. 

“What is this?” Seteth asked, voice startling Felix out of his battle concentration. He was breathing heavily, sword in hand. 

“The Demon was sparring with me. I found it interesting to fight something with an extra appendage for utility. It’s rather useful.” The boy straightened his hair again and smirked over at Byleth, who watched the Priest. 

When Seteth glared over at her with unease, she cleared her throat. “ **I was putting myself to use, though we attracted quite a crowd. I believe they want a turn.** ” 

Seteth’s gaze remained steady, appraising the situation, picking it apart piece by piece as if to check and make sure there weren’t any evil undertones that Byleth could have snuck in. Felix seemed to pick up on the tension as he backed up, picking up the weapons they’d scattered as Byleth continued to disarm him throughout fights expertly. When Seteth couldn’t find an ulterior motive, he cleared his throat and looked at the line. “Yes, well, I suppose that’s acceptable. However, I am afraid I must end the _session_ for tonight.” 

“Awwwww!” 

“But, I wanted to beat up a Demon!” 

“C’mon guys. Professor Seteth needs to reign in his pet.” 

The murmurs rippled through the line of students. While some of the comments were a bit more aggressive than Seteth would have expected, they were not off-color for what they technically stood for at the Monastery. His gaze flicked to Byleth as if reading her reactions. Her stony face betrayed no emotion as she moved to follow him, tail swishing behind her as if unphased by the comments. Even as they sneered as she passed, emboldened by Seteth’s presence, she paid them no mind. Wolves did not concern themselves over the opinions of sheep. There was no use raising her hackles against children. She was eternal, and they were but snowflakes in the quiet morning before a warm day.

\---

Seteth had a few things planned for his evening, but since none of them involved students, he could easily keep Byleth around to keep her from trouble. Despite his previous threats, she’d gone out of her way to annoy him further, pushing him closer and closer to a snapping point. Knocking a book off of the table with her tail as she passed, loudly sighing as he tried to sift through a few books, and making the occasional noise when he’d almost gotten to the bottom of a particularly lengthy page of text. 

But still, he didn’t crack. 

Byleth had to hand it to the Priest; he had a wealth of patience. To her credit, she’d managed to make it through the day with seven new commands he'd been forced to make. It not only proved her theory correct - that he had no idea how to deal with her - but also fueled her amusement. She had to do _something_ to keep entertained, after all. Even as Seteth prepared for bed, Byleth continued to plot. 

“I don’t like how silent you’ve been. What are you planning?” Seteth slipped under his covers, blowing out the candles on the nightstand next to his bed. Smoke wafted in the moonlight, catching her attention for a few moments as it slowly dissipated. Her reflective eyes slowly slid down his silhouette, almost predatorily. 

“ **Hmmm. Well, I could fill the silence with something. Perhaps a lesson on Demonic history?** ” She stood from her perch by the window, tail brushing against the tie that held the curtains tied back from the window. They fell without a sound, covering the only source of light to the room, shrouding it in darkness. Judging by Seteth’s silence, he didn’t seem too thrilled with the prospect. Byleth crawled onto the bed, feeling the Priest stiffen within the covers.

“I would like my personal space while I sleep, please.” It was easy to imagine him becoming flustered as he had earlier, tips of his ears burning red. 

She continued closer, dragging a clawed finger up his side gently. “ **I’m sure we could fill the silence with** ** _something_** **. Put those taut muscles to the test-** ” 

_"T_ _hat is enough!_ ” 

_Oh. That might be it._ How easy it had been to slowly burn at the man, only to watch him implode and crack in the dark. While it was regrettable that no one was around to see him crumble, she took it as a personal victory. So why didn’t she feel better? Fulfilled?

Seteth threw the covers off in an angry flourish, knocking them into Byleth as he angrily began to dress once again. As she’d suspected, the tips of his ears were red. It wasn’t until he spun around to face her that she realized it wasn’t with fluster, but with fury. “I _will not tolerate this behavior any further. You want me to make you earn your respect? Fine. Follow me._ ” His eyes bore into hers angrily. “ _I’ll play your game, and I'll beat you at it._ ” 

Byleth blinked a few moments, clearly taken aback by the frigid glare. “ **Where are we going?** ” 

As Seteth tore off in an angry walk towards the door, she barely caught his angry huff. “The Training Grounds _._ ” 

  
  


**Notes for the Chapter:**

> Man it's starting to get fun
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	5. Yield

**Summary for the Chapter:**

> Seteth challenges Byleth to a Duel on Demon terms.
> 
> Byleth learns what kind of human Seteth is.

Seteth hadn’t uttered a single word as he weaved through the dark corridors of the Monastery. Tall, ornate pillars cast shadows in the moonlight that Byleth would’ve enjoyed lounging in, but instead, she was stuck following Seteth. Kicking him unceremoniously over the edge with her petty annoyances had been fun, and while this promised to be equally entertaining, it was probably a lot of effort as well. Her limbs still felt heavy from the previous night’s fight, wounds unhealed until she could recharge her magic. She had no doubt he was leading her for a spar. 

Byleth would consider her unhealed injuries as a handicap for the fight and reveled in the delicious irony when she eventually trounced the Priest. 

The Monastery was not without its rules. Students were sleeping by this hour, and if they closed the Training Ground’s large, heavy doors, they’d be free to duke it out to their heart’s content. It was clear the Priest felt as though he had something to prove, so who was Byleth to deny him? Strength was letting your opponent realize the exact difference in power, and victory was the steps one was willing to take to achieve it. 

The heavy oak doors groaned as Seteth pushed them open with a grunt, holding it ajar for Byleth to slip inside. _Ever the gentleman, even as he fumes angrily_. When both of them were inside, he let the door close with a heavy click. “You were correct earlier, Demon.” His voice pierced the silence, warm breath forming wisps as he spoke in the fresh night air. 

“ **Oh?** ” He certainly knew how to catch her attention. Despite herself, her ears flicked up with interest. “ **Do tell. I always** **_love_ ** **hearing how I’m correct.** ” 

“Of course you do. I did not have any ideas on how to… _handle_ you.” Seteth’s hand began to glow with bright white magic. After a moment, the torches that outlined the Training Grounds roared to life. The crackle and popping of the wood made Byleth feel at home. 

“ **Well, I had a couple of ideas, but you didn’t seem too keen on those…** ” 

The Ashen Demon took delight in the sheer annoyance that ebbed off of him in waves. “Silence. You know very well what I meant. I _have_ been pushing you on others while I tried to figure out how to deal with your behavior. It wasn’t until we spoke on the way to this very place earlier that you gave me the answer yourself.” He reached for sparring tape, dextrous fingers beginning to wrap his hands to protect them. Byleth merely watched, amused. “You said it yourself. I have to tackle every problem head-on. I cannot properly research this sickness _and_ wrangle your ridiculous antics every minute of the day. I will earn your respect, and you _will_ acknowledge what it is I am attempting to do. You do not have to agree, but I will make you see me.” 

As much as Byleth struggled against it, she was relatively impressed. However, the Priest would need more than pretty words to defeat her. “ **Bold, pretty words coming from someone who could only take me down after I’d solved your little** ** _problem_** **for you**.” 

“Then this should be easy for you.” 

Byleth physically bristled. “ **Yes, it should.** ” The way he said it… The smug sureness, where had his anger gone? Flustered opponents were opponents that couldn’t adequately fight back. Mental antagonization was a valid tactic, whether the pious liked it or not. 

Was he doing the same to her?

Worse off, was it working?

“ **Bah. Let’s get this over with. I’ll have you begging me to allow you to release the contract by the end of the night.** ” Cracking her knuckles, Byleth stared down her opponent with slitted eyes. Seteth paid her no notice as he took off the outer robe he was wearing, allowing it to fall to the stone below. The simple shirt he wore underneath revealed the body that the Demon hadn’t quite believed belonged to the bookish Priest upon first glance. He’d proven her wrong once before, but she wouldn’t make the same mistake again. 

He returned her slitted glare with a steely, cold expression of his own. “I am ready.” _How polite._ If manners made the man, did the lack-of make a Demon?

Byleth wasted no time to rush her lone opponent, dropping to all fours temporarily to close the distance quicker. Her eyes glanced to the right, and her body was poised to leap to the right, but the weight of her tail threw itself to the left to let momentum allow her to cease and fake Seteth out. The same tail that helped her dash to the left swept at Seteth’s legs in an attempt to knock him over. 

Seteth’s jaw set as he jumped over the swinging, draconic appendage with ease. “ **How many tailed Demons have you fought against? Do not treat me as a human opponent.** ” Her jaw clenched in frustration as Seteth landed on his feet. In a typical spar, the Priest wouldn’t have to worry about counter attacks in such a situation. However, given Byleth’s flexibility and maneuverability of her tail, he hadn’t been expecting the kick to his stomach. It all but knocked the wind out of him, sending her opponent flat onto his back with a grunt. 

“ **That’s not a good look for someone that talked such a big game.** ” The Demon teased, the tip of her tail flicking back and forth as she crouched. After her shoulders wobbled ever-so-slightly, she pounced forward with claws outstretched. 

Thinking quickly, Seteth lifted his knees so his feet could connect with her stomach. Her momentum would be enough for him to send her reeling. 

So that’s exactly what he did. 

His strong hands gripped her waist as she jumped into his legs. “And this isn’t a good look for someone who fell from humanity. Time to fall again.” He rolled back a bit with force, using his arms to keep her steady before kicking her away from him. The sound of her claws scraping against the stone floor gave him gooseflesh, eerie echoes making the sharp sound linger. She’d managed to slide on all fours, tail keeping her from slamming fully into the wall. 

Seteth lacked the dark vision that she had, but her look of shock and offense was all too clear in the torchlight as he rushed her. “ **Is that what you think Demons are?! Broken husks of humanity?!** ” She dodged his right hook effortlessly, ducking under the strong arm and using her tail to spring forward. Their positions were now reversed with Seteth closest to the wall. Her foot slid on the smooth stone as she pivoted, clawed hand grabbing Seteth’s throat with shocking speed. The force didn’t stop as she slammed him against the wall, muscled arms raising him off the ground.

“ **I assure you, if that is what you truly believe, you are very-** ” The words became accented with her tightening grip. “- ** _very_ ** **misinformed.** ” If he were trying to rile her up with lies, Seteth was doing an excellent job. If this was news to the Priest, his eyes didn’t show it as he dangled in her grasp. Despite the advantageous position she had on him, Seteth refused to struggle. He would give her no joy in this: he was not wriggling, mewling prey that would beg for their life. Byleth picked up on this, nose wrinkling in distaste. “ **Well, you don’t make it very fun, do you?** ” 

“I figured it would be more fun to deny you that pleasure.” His remark was breathy, Byleth’s grip on his throat tight but not wholly restricting. A strange, grating rumble began to emanate from her chest. 

“ **Perhaps you know how to have fun after all…** **And here I thought you were timid. Yield.** ” Since there was no struggle, the position wasn’t hard to maintain on Byleth’s arms. Seteth would struggle for air soon, though. Her grip relaxed slightly so she could hear his surrender loud and clear. If only there were a student up to see their teacher fall in defeat…

Pressure alleviated, Seteth swallowed and stared down at her from the bottom of his eyes. “This is the only ‘fun’ I want with you.” He all but growled, body surging to life. His right knee shot up, clocking her in the chin and mouth while his left leg pushed against her chest in a hefty kick. The combination of blows staggered The Ashen Demon, who was forced to release Seteth and attend to her bleeding lip. “You have a contract on me, yes? There’s your blood offering.” 

_Cheeky bastard_! Byleth’s posture changed, her back arching as she stretched. Monstrous scales began to cover her small portions of her exposed skin, including a quarter of her face. “ **Careful. The Demon might come back for more.** ” 

Seteth didn’t skip a beat. “The Demon is going to get more until it learns respect.” 

Byleth’s eyes narrowed as she charged once again, blood continuing to stream down her chin. If the students and staff woke to pry Seteth’s broken body up off the stone floor, then so be it. She would not be mocked again. As the monstrous entity surged with rising anger, Seteth’s eyes darted to either side of him before deciding on his next move. The Ashen Demon lowered her head to ram into Seteth with her horns, but the impact never came. 

Instead, the cloth of his shirt did. 

They weren’t necessarily heavy, but her sharp horn pierced the delicate fabric, slipping down the length of it. From there, it flapped in her vision, blocking off all sight of the Priest, overwhelming her nose with his scent so she couldn’t differentiate his actual location. Magic surged around her as Seteth charged an attack. “ **Fuck!** ” Her clawed hand grabbed at the clothing to rip it in _just_ enough time to duck out of Seteth’s rapidly approaching punch, fist enveloped in the white light he’d used earlier. 

It was a smart trick; she had to give him that. Utilizing his clothing was something she hadn’t expected from the sternly chaste Priest, and yet here she was staring down her now-shirtless opponent. “ **You know, I think you look better like this.** ” She purred, cocking an eyebrow. The magic around his hand faded, but the presence of white magic hadn’t disappeared. It wasn’t until Seteth jerked his hand to the side that she realized there was a bolt of light suspended behind her when she’d been temporarily blinded. He took advantage of her distraction as the white-hot magic seared her back. 

“ **Argh!** ” Pain radiated from the wound, his prior words from the lecture echoing in her mind as he utilized one of her weaknesses. “ **Fucking… Priest..!** **Are tricks all you can utilize?** ” 

“As the Demon of Victory, surely you understand that it does not matter how one achieves it, just that it is achieved.” 

“ **Don’t patronize me.** ” She spat, blood spraying the ground beside her. 

Seteth was unphased. “Then be better.” 

Byleth took a deep breath and cleared her mind, refusing to fall for his mind games. She didn’t have enough magic to heal herself, but she did have enough for this. Black miasma seemed to seep out of cracks between the cobblestones below, pooling at Seteth’s feet as she lifted her clawed hands. Alarmed, he tried to step back and out of the dark magic but found himself stuck in place. “ **Yield. This is over.** ” 

“No.” He was just as challenging as she, the spark of determination all but blinding. 

Her bare feet hardly made a sound as she padded forward, moving so she was almost toe to toe with the human that, by fluke, had managed to contract her. She was just out of his striking range. “ **Yield.** ” 

Once again, Seteth refused. His chin rose in defiance. 

With a few quick steps, Byleth closed the distance between them, slamming her forehead into his with a sickening _crack_. The magic disappeared at Seteth’s feet as he crumpled to his knees, chest heaving ragged breaths from the impact. Just as blood oozed down her back, it began to stream down his face. Her tail slipped across his neck to lift the chin that had, just earlier, been cocked with such _delicious_ defiance. He met her gaze before she kicked his side, sending him sprawling onto the ground. He rolled limply as he struggled to regain his senses. As she approached, Byleth’s voice was a low growl of amusement.

 **“Your pretty words are not enough to defeat me. Though, I should have known that pretty words were all anyone in this Monastery would have. Your curriculum is wrong, and you were wrong to think I’d ever respect you. You had guts challenging me, but guts only belong on the battlefield, spilled before me as I relish another victory.** ” She padded dangerously closer as Seteth regained his balance, rising to his knees once again. 

“You would do well to remember I won the first fight between us.” Blood dripped off of his chin and down his chest, the colors in stark contrast. Byleth couldn’t help but relish the picture before her: A defeated warrior on his knees, blood painting a picture across his battered body as the shadows from the torchlight danced across his well-muscled form. 

Were she losing like earlier, the words would’ve riled her. Instead, the grating purr rumbled from her chest once again as mirth dripped from her words. “ **Cute. However, we both know that time didn’t count.** ” 

Her picturesque subject of study let out a barking laugh, wiping at his mouth with a bare forearm, smearing the blood but keeping it out of his mouth. “Is that so? How convenient for you.” 

“ **The only one who utilized convenience was you. You used me, waiting until I had all but razed your battlefield for you, and then bound me with your trickery.** **I have had enough of these games. I will force you to yield and put an end to this farce.** ” The Demon approached him again, lifting her leg to kick Seteth in the face. 

The moment she lifted her foot, Seteth dropped to all fours and slid under her legs, cold hands grabbing her tail. With a grunt of effort, he yanked. _Hard_. While the maneuver didn’t hurt per se, it was enough to throw Byleth off balance and onto her back. Horns clacked against the stone, forcing her head into the awkward position once again. Seteth looked as though he were about to pin her, so she jerked her head forward so he couldn’t. 

It proved to be a mistake.

His hands wrapped around a set of her horns, testing the grip before his body surged with magic. It pulsed through his veins, bolstering his muscles with white-hot power. Byleth reached out in an attempt to slash at his bare chest, but Seteth wrenched her head to the side. It was all she could do to comply, unable to fight the vice-grip on her horns. 

Strength increased, Seteth let out a hiss, growing into a yell as he chucked The Ashen Demon across the Training Grounds, slamming her body into a training equipment rack. The wooden weapons rattled and fell to the ground, Byleth quickly following suit. 

Seteth was on top of her in an instant, straddling her hips as his legs weighed down on her own. His calloused palms pressed into her wrists, successfully pinning the beast amid the scattered weapons. “ **I… I told you not to treat me as a human opponent..!** ” She hissed, tail lifting. It slammed into his back, but the force wasn’t enough to make him budge. She tried to do it again, but his shin crossed across her own so his foot kept her tail at bay. 

The space between them was tense as the torches crackled above, chests heaving with their exhausted breaths. His eyes bore into hers, searching for a hint of her next action. A next move. Whatever trick she would attempt. When nothing happened, Seteth’s voice pierced the silence. “Do you yield?”

“ **...** ” The Ashen Demon was flabbergasted, pinned beneath the Priest. The more weight he pressed on her, the more her seared back cried out for relief. She could feel the chill of the night air on her skin, slick with sweat and blood. Whoever was to clean up after their fight had quite the task ahead of them. 

“Do you _yield_?” He pressed harder with his arms, pulling Byleth back from her thoughts. “Gain control over the situation, and the troops' respect follows shortly after.” 

Hearing her own words out of his mouth made her stomach flip with revulsion. Her lips pursed for a moment before she spat off to the side, blood trickling from the edge of her mouth. Seteth couldn’t make her give up. The only thing he could do was give in to her stubbornness. 

Her suspicions were confirmed when she felt the pressure on her wrists let up. A wicked smile rose to her face as she closed her eyes in relief. _Of course, he’d roll over like the soft human he was-_

Seteth’s fist connected with her face. 

The Ashen Demon’s head rocked to the side, coughing up another mouthful of blood from the impact. Stars danced on the edge of her vision as her eyes fluttered open in shock. He was sitting up, staring down at her as her blood dripped from the knuckle tape on his right hand. “Yield.” 

It was not a command. It was not something she had to follow. He was no longer hiding behind the stipulations of the contract. She blinked up at him. The man who’d bested her in combat not once, but twice, as much as she hated to admit it. The man that played by her rules and beat her at her own game. 

The man who would make her yield of her own accord. 

The words were hard to verbalize, but when Seteth’s arm raised for another blow, her shoulder’s sunk to the ground in defeat. “ **... I yield. You win.** ” 

Seteth’s arm continued to move, and The Ashen Demon flinched, expecting another blow for good measure. He’d put her in her place, and there was no denying his prowess in battle, what better way than to let your opponent know just how outclassed you were? The impact never came. Instead, his thumb brushed against her lip as white healing magic bloomed under his touch. The split from earlier in the fight began to form back together as both his hand and Byleth’s Cichol brand shone with a bright light. 

She would never understand humans, especially this one. 

His careful hands took care of her wounds, even the ones she’d suffered from the battle with the Monastery beasts the night before. The magic didn’t burn so long as the brand on her chest was alight, probably connected to Seteth’s intent. When the only injury left was the one on her back he promptly removed himself from the compromising position they’d been in. His hand reached out to assist her up. Byleth watched it with suspicion. “ **I don’t understand**.” 

Seteth crouched and grabbed at one of her wrists to pull her up onto her feet. A decent puddle had formed under her as she’d been forced to lay in her own blood. His cold fingers brushed against the open wound but instead of wincing Byleth felt… nothing. Fingers traced the circumference of the injury, and after he’d looped it in its entirety, The Ashen Demon was whole once again. “We may not see eye to eye, but like it or not, we rely on each other to an extent. I need your assistance here, and you need me to stay on this plane. I accomplished what I sought out to do, but I would be a poor leader if I left you in such a condition.” 

Fully healed, Byleth’s gaze trailed up to Seteth’s forehead. He’d not just healed her wounds. He’d treated her before himself. For someone whose revulsion in her presence was hardly concealed, he’d certainly kept his composure throughout the entire fight. There was a lot to unpack, but the Priest didn’t give her long to mull on it. He turned to where he’d deposited his robes, limping slightly as his hands began to heal the various wounds across his own body. Clothing in hand, he draped the robe across his shoulders and opened the heavy wooden door with a metallic ‘click.’ Without another word, he slipped away into the darkness, leaving Byleth to her thoughts and the crackling of the torchlight. The bright flames seemed to dance in celebration for Seteth’s victory, mocking her loss and surrounding her in a fiery ring of blasphemous disappointment. With a snap of her fingers, all of the lights went out.

She’d never felt further from home as her fingers trailed over a freshly healed lip.

**Notes for the Chapter:**

> This one was a lot of fun to write! Things are starting to smooth out for our angry duo.
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	6. Chocolate

**Summary for the Chapter:**

> Byleth is given a job suited for her... talents. 
> 
> and
> 
> Byleth makes a friend?

Byleth was completely immobilized under Seteth, his chest heaving as his fist connected with her face. The force of the blow rocked her chin to the side, blood spattering from her open mouth. He could see the sharpened edges of her teeth, just as dangerous up close as they seemed from afar. As much as he knew the blow hurt, he understood enough about the demon to acknowledge that the pain she was feeling wasn’t physical, but to her pride. From what he knew of their society, everything was based on a hierarchy of power. The moment you fell from your pedestal is the moment you were eaten alive by the competition you had previously stepped over. Her body writhed under his hips, her eyes rolling as if in a daze. 

He hated to resort to violence, but it couldn’t be helped. If _this_ , whatever perverse contract they had was to work, then they had to be on equal footing. If that meant dealing with her the ‘Demon’ way, then so be it. Knocking her down a pedestal, and climbing up one in return, left them side by side to tackle the problems he faced. 

But only if she yielded. “Yield.” _Please, Goddess, yield._

This was the first time he’d been close to her in visible light. The flickering torch fires illuminated their dueling space, casting shadows over her face. Every scar, scrape, and speck of blood was on full display for him to see as he looked down at her, the defiance in her eyes morphing into something entirely different. In battle, where she thrived, it was difficult for Seteth to deny the… beauty she brought to the battlefield. 

But, it had no place in the Monastery and no place in his thoughts. 

He raised his fist again, clearly ready to force the answer out of her if possible. Her shoulders sagged to the ground as she admitted defeat. 

There was no point in asking for anything further, or twisting the knife of victory between her ribs further. Magic surged in his palm as he reached out, almost absentmindedly, to brush his thumb across the giant crack in her lip. He watched the skin heal up at his touch, eager to finish so he could return to his chambers. Many people depended on him to lead, and if this worked tonight, then he’d actually be able to devote the time and effort that was required for that. 

Byleth allowed him to heal her, his hands only pressing against the necessary skin. As soon as he was finished healing everything but her back, he assisted her up and moved to fix that as well. The bare minimum was done, and the impersonal healing session was finished. Her confusion voiced, he answered. “We may not see eye to eye, but like it or not, we rely on each other to an extent. I need your assistance here, and you need me to stay on this plane. I accomplished what I sought out to do, but I would be a poor leader if I left you in such a condition.” That was it. He turned to heal his own wounds and began the cold walk back to sleep. 

\---

Seteth and Byleth returned to their shared chamber, neither one saying much as they prepared for bed. Seteth had healed their physical wounds, yet Byleth’s phantom pain lingered. The war Demon could recall every injury she’d ever received in vivid detail, from the lucky soul that inflicted it to the length of time it took for the pain to disappear. So why did these two injuries feel different?

" **...** " Troubled, Byleth sat in her pile of blankets and took in a deep breath. After a few moments, her eyes closed as she worked towards a meditation. Seteth, who'd finished toweling off his hair, watched with mild interest. Was it a post-battle ritual, or something she did when she'd lost?

" **I can feel you staring.** " She didn't seem annoyed, instead focused and concentrated. The Priest cleared his throat and returned to his nightly ritual, ready to salvage however many hours he could before duty called.

"Yes, well, I can feel your… discontent?" His fingers brushed experimentally against the crest on his chest, causing Byleth to shudder slightly. As he approached, she turned to look at him over her shoulder, suspicious. _You've already won. I get it._

" **What do you mean,** **_feel_ ** **it?** " 

Seteth sat at the edge of the bed, watching her tail curl around her person, resting in her lap. "If I understood, perhaps I could articulate it better. After healing your wounds, it's almost as if I can understand you better." 

" **Just because I don't** **_enunciate_ ** **like you doesn't mean I'm not able to be understood.** " 

The Priest rolled his eyes, sensing her wounded pride. "No, I mean your emotions, surprising as that may be. I have no doubt you can feel mine as well." 

Byleth smirked, turning around to lean against the wall beneath the window, tail splayed out in the moonlight. " **I don't need a stupid bond to read your emotions. You wear them in your face.** "

"And you do not. Outside of the occasional smirk, you are rather unexpressive. I have been relying on the tone of your voice and body posture to assist me, but this is fortuitous." 

The Demon closed her eyes and searched for the light tug of the bond. What could she glean from Seteth with this? She'd already established these worked both ways. His words mostly rang true, though laced with the occasional string of doubt. Previously, she would've attempted to use it as a jump rope. But that was before he'd earned her respect. " **You do not feel very confident in it, though.** " 

Called out, Seteth crawled to the head of the bed and slipped under the covers. "You are correct."

" **Why?** " Her eyes blinked in the darkness, chin resting on the edge of the bed as she watched him. Seteth cleared his throat and rolled over, looking away. " **Come on. We're pushing day three. We're practically best pals.** " 

His sharp bark of laughter made her smirk. "Hah! Hardly. If you must know, I do not trust you. You may speak that this is how Demons operate, but how am I to know if this is true?" 

" **You might have to go out on a limb and trust me.** "

Seteth's nose wrinkled. "Impossible."

" **I've been undefeated for a thousand years. Nothing is impossible; your species is resourceful. If I get to have an existential crisis on the solidity of my identity and the validity of my existence when my core values have been shaken,** **_you_ ** **get to have one about stepping out of that tightly-wound box of comfort and take someone else at their word."** Byleth watched the Priest's shoulders rise and fall with his breathing. When he didn't stir or reply, she continued. **"What kind of** **_General_** **would I be if I didn't trust my troops?** "

After a bit of shuffling, Seteth rolled over onto his other side, facing Byleth. “I would be lying if I said I was not troubled by some of the things you said earlier. Bits about our knowledge of you being incorrect, and well…” He trailed off. “The person I would normally ask questions of this variety is the very one we will be using your assistance with.” 

Byleth couldn’t tell if the heavy feeling in the room was from him, and she was picking it up via their bond, or if it was her own. Already experiencing emotions outside of her usual (anger, pride, confidence, rage) ones made for complicated mental acrobatics. “ **When are you going to let me see her?** ” 

“I do not know. I… need to trust you first. If I lost her, if Garreg Mach lost her, I do not know what I would do.” The weight continued to press against her chest. 

“ **Is she your mate?** ” She did not know the precise terms humans used these days, but figured by the flustered wave of anxiety that suddenly rippled through her (courtesy of the Priest, of course) that he’d interpreted the statement well enough. 

After his emotions caught up with him, Seteth cleared his throat. “No, she is not. I do not have a mate, only a daughter, and a dear friend.” 

“ **I see. Well, we won’t get anywhere until you trust me enough to let me look at her. Until then, I guess I'm just here.** ” 

“I guess you’re just here. We will look at some books tomorrow. Rest up. There’s much to be done, and we have already lost most of the night for sleep.” 

\---

Seteth woke up at the same time he always had, per routine, hours before the sun itself. There was still work to be done, but ever since their spar, The Ashen Demon had relaxed her rebellion. Seteth's productivity had increased, allowing him more time with Flayn and less worrying about the beast he'd subdued. The tug of their contracted bond was like a heavy weight at times, a crushing reminder of its presence, but most of the time they managed to coexist well enough. There were some days, a rare ray of light on an overcast day, where he'd forgotten about the contract entirely. Byleth could be… palatable, in her own fashion, but only when she wanted to be. Seteth appreciated the self-control she'd been exhibiting over the past month. 

He stood and walked around the corner of his bed to where she slept, curled up under a blanket on her side. It was the only position her horns allowed for unless she slept on her stomach. When he inquired one night about it, she mentioned something about reaction times or feeling uncomfortable. Seteth hadn't pressed. 

She looked almost peaceful when she slept, untroubled by the contract or Seteth's errands. Usually he would wake her so they could get started on the day, Seteth teaching while Byleth studied a few texts for more information on coma sicknesses, but something stopped him. Divine intervention? A nagging thought? Whatever it was, he proceeded to get ready as quietly as possible. Their Demonology discussion could wait. Byleth snoozed, rolling over to curl her tail closer around her. 

As much as he distrusted her, the display was rather adorable. Rolling his eyes at the intrusive thought, Seteth adjusted his circlet and left the room so Byleth could rest. 

\---

The Ashen Demon was alone, ferally crouched over a defeated enemy as more ran towards her. In her dreams she was always fighting, always winning. As her claws slashed out to dispatch foe after foe, the shadow she cast in the fires of her destruction grew until it was a roaring, grotesque beast behind her. Those who saw it turned on a heel to run away, terrified. 

It was the same style dream she'd had for years. Hundreds, maybe thousands of them. 

“ **Child’s play**.” She rumbled, amused. The fire crackled, the smell of smoke and ash dominating her senses. “ **Maybe one day the poor souls in my dreams will see why I am called The Ashen Demon.** ” Her shadow roared a bestial sound. 

Byleth turned around, eager to walk through the battlefield to find more opponents, but stopped in her tracks at a sudden change of scenery. What had always been a vast field of strewn bodies and fire in every dream she’d ever had, a massive mirror stood instead. It was as wide as it was tall, as far as her eyes could see in either direction. When she looked up, it seemed to split the world in half as it rose into the clouds. “ **This… is new.** ” 

When she looked for her reflection, there was nothing there. “ **Preposterous.** ” She growled, approaching to place her fingers on the smooth surface. It rippled, like water, tiny waves emanating from her touch. As the watery surface of the mirror stilled, Byleth could see her reflection begin to form, and yet… it was different. 

This Byleth lacked horns or a tail. Her ears were round, like a human’s, and her eyes were bright and blue. When The Ashen Demon lifted her left hand, the human Byleth did the same. “ **No! What is this?!** ” Her fanged yell reached no one else’s ears in the dreamscape, the human Byleth yelling with the same intensity without sharp teeth for biting enemies. Everything in her body identified with this _human_ woman before her, a hint of familiarity to her but not enough for Byleth to fully recognize. 

Her breath began to pick up in speed, clawed hands checking the various bits of armor and clothing Byleth wore. The human reflection did the same, carefully unfastening a piece of armor to let it fall to the ground. It’s reflection followed suit, movements in tandem with the glassy visage. The Ashen Demon could smell her own fear, a sharp, acrid scent that she’d almost forgotten. “ **This is not me! I am The Ashen Demon!** ” 

_But what does that mean? What am I, if I am not the embodiment of victory?_

_Is there… more? More to life than just what I was made for?_

The questions hissed like snakes, coiling into her thoughts and insecurities to squeeze any familiarity Byleth clung to until she felt short of breath. “ **It’s the bond. It’s not me! This** ** _is not_ ** **-** ” Her finger shook as she pointed at the reflection. 

It pointed back. 

“ **-me!** ” 

Byleth awoke with a start, fangs bared and chest heaving with both fear and rage as her eyes adjusted to the bright flood of light that streamed through the window of Seteth’s quarters. Her hoard of pillows and blankets was disheveled, a blanket lodging her tail and foot under another as if she’d been kicking. The sunlight was warm but caused her a bit of confusion. Why was she still sleeping? Suspicious eyes flicked over to Seteth’s bed, noting that it was neatly made and empty. Judging by the amount of sunlight flowing through the window… It had to be mid-afternoon. Was today a day of rest?

The night certainly wasn’t restful, that was for sure. Byleth could’ve sworn Seteth had mentioned something about discussing Demonology with him today, but perhaps she’d dreamed that too? 

“ **Fuck dreams.** ” She growled, nestling back into the pillow nest she’d created. “ **If I’m allowed a free day, I’ll take a damn free day.** ” 

\---

Unfortunately, free days that involved sleeping in often included missing lunch. She’d yet to make friends within the kitchens, so getting food outside of Seteth or Claude’s assistance was typically tricky. When she’d made a joke about helping with the stray dog population, the kitchen staff eyed her angrily. So, she was forced to wait. Claude was in a lecture, and Seteth was doing Seteth things, so she took to finding a warm, sunny spot in the garden to relax in. Students gave her a wide berth, whispering under their breath as she passed. 

A wave of annoyance washed over her, stemming from the crest on her chest. Someone must’ve crossed Seteth in class, or perhaps it was Claude giving a dumb answer? His emotions mingled with hers, tail flicking from side to side with the impatience that he felt. _Excellent. Not only do I have to deal with my own, but his as well_? As she climbed to the top of one of the gazebos to stretch out, she let her tail hang down to dangle haphazardly above the tea table. The students at said tea table gasped, standing and quickly leaving the area. Too bad their snacks had already been eaten, or Byleth would’ve scooped them up. 

She rolled onto her back, tail lounging lazily off to the side as she closed her eyes. There wasn’t much happening in the gardens, leaving her to enjoy the sun in silence. Save for… small footsteps and the overpowering scent of baked goods. 

“Excuse me, I’m sorry for bothering your sunning, but-” A tiny hand pulled at the end of her tail gently to catch her attention. Byleth rolled over, tail gingerly slipping out of the hand’s grip. Her slitted eyes honed in on a young girl with large curls, her green hair akin to Seteth’s. “I didn’t see you at lunch with Seteth, so I was not sure if you ate or not.” 

Astute observations. “ **I did not eat.** ” 

“Well, if you would like, I'm going to put a chocolate pastry on the table here. If you like it, let me know and I can bring you some more sometime.” The young girl didn’t seem very fearful of her, more curious of the Demonic entity lounging than with her own personal safety. Her hand rummaged through a small basket before producing a wrapped good that smelled sickly sweet. Byleth’s stomach growled against her wishes. "Also, I like your horns. They're very pretty." The young girl waved with her fingers before she slipped behind a hedge and out of view. After a few moments, the scent of the basket was gone as well, leaving a semi-stunned Byleth with the baked good. _Pretty?_

When she was sure no one was watching, Byleth hopped down and retrieved the food. Chocolate drizzled over the sweet delicacy, all but begging to be eaten. They certainly didn’t have anything like this back home. With a few eager chomps, all evidence she’d been given a gift was gone, and her immediate hunger was satiated… for now. But why did the girl provide her with something in the first place? Was she a student? The Ashen Demon had been here long enough to memorize the colors of uniforms. She had a lot of questions and no answers, but at least she had a new appreciation for this ‘chocolate.’ 

\---

Seteth pinched the bridge of his nose as he leaned back in the chair of his office, taking a short break from all of the paperwork he was processing. Student papers, grades, Monastery funding, Monastery issues, Rhea's illness, and now this strange presence skulking about the Monastery at night? The last thing Seteth needed was _another problem_. When he felt like he'd crossed one off of the list, another reared its ugly head. Or at least their horned head. 

He needed to give The Ashen Demon a bit more credit. After their fight, they'd done well to not step on one another's toes. In all honesty, he'd expected her to kick down the door and inquire about the change of schedule. They were supposed to discuss the possibility of a Demonology information exchange, but he'd stopped himself from waking her. It was early evening by now, and he'd not heard a single word from, or about, her. The Priest was unsure if he should be suspicious or relieved. 

No matter the outcome, he'd sent Claude out to look for her and bring her back. Demonology would need to wait. Perhaps the nagging feeling he had about waking Byleth early had to do with sending her after the mysterious dark knight the rumors swirled around? The first month of their contract was coming to a close, so perhaps allowing Byleth to defeat something would satisfy some of her stipulations and give her something to do. When Claude peeked around the corner of the doorframe with Byleth in tow, Seteth beckoned for them to come in. Byleth was already halfway through the doorframe, either unaware of the etiquette or uncaring. 

Seteth supposed either or both could be true. "That will be all, Mister von Riegan. Have a nice night." Byleth leaned against the wall beside a window, inhaling deeply. 

Claude lazily saluted at Seteth before waving to Byleth. "You don't have to tell me twice, Professor Seteth. Have fun, you two." When the student left, he was sure to close the door behind him, leaving Byleth and Seteth in silence. 

Byleth broke it first. " **You wouldn't happen to have any fo-** " 

"Here. You slept in so late. I figured you would be ravenous by the time dinner came." Seteth pulled a wrapped basket from under his desk, sliding it across the surface in her direction. Her eager claws rifled through its contents, eating ravenously. He couldn't be sure, but he almost felt gratitude through their shared bond. While she was content to consume, Seteth spoke. "I was surprised I hadn't heard from you or about you today.”

Between messy mouthfuls, Byleth answered casually. " **I recognized your strength almost a moon ago. I haven't caused trouble since then. Is that not what you wanted?** " Bones crunched between her teeth as she ate cooked bird ferally. 

Seteth cleared his throat, only slightly taken aback. "That is true. It is because of this that I am giving you an assignment." The Demon's ears flicked. "The first moon is nearing, and I believe there are some stipulations on your end of the contract that needs to be addressed." If Byleth hadn't been paying attention earlier, she certainly was now. Her eyes bore into his with intense interest. "There is talk of a strange figure skulking about the Monastery grounds at night. I did not wake you this morning because I would like for you to begin patrolling the grounds to catch this individual. You are free to do with them as you wish, whatever your _contract_ requires." 

" **Battle. Victory. If I'm lucky, I'll get a scar out of it.** " 

"Charming.” The sarcasm in his statement surprised him, but Byleth only smirked. The bond went both ways, indeed. “Well, whatever the case may be, we have reason to believe that he is not working alone. If you have a reason for concern, do not hesitate to bring the culprit to me. If we can get information, it would be beneficial. The reports are disturbing." 

Byleth could feel the discontent and fear through their shared existence. " **You are fearful.** "

Despite himself, Seteth stiffened. "Yes. Young girls are being targetted, and while it is already disturbing that we have this problem in the first place, knowing that the youth of Garreg Mach are in danger is cause enough for me to be very fearful. I want this criminal apprehended before someone gets hurt."

The sliced slab of chicken finished, Byleth moved on to a delicately sliced loaf of bread. " **It is a shame. Real victories are pulled from enemies of a similar caliber. There is no honor or glory in picking off younglings.** " 

Seteth blinked. Once, then twice. "That is... something we can agree on." 

" **I'll do it. I'll start now. I've spent enough time avoiding you to know the good spots to hide.** " Her dry laugh caused the edges of his lips to turn in the slightest of smiles. 

"Excellent. If you can get information, all the better." 

" **Yeah, yeah. I'll get your information, so long as I get my battle.** " The Demon closed the basket and pushed it back towards him. Seteth's quick hand stopped the woven container before it careened into the stack of papers he'd so diligently worked on all day, fighting back irritation as he watched Byleth approach the exit. Hand on the doorknob, she paused as her tail swished idly. " **One final thing.** " 

"Yes?" 

She took a moment as if finding the words. " **I am... sorry. Neither of us were on our best behavior, but working together will make however long this ridiculous contract lasts easier. But-** " She whipped around to stare holes through him over her shoulder. " **-don't you dare mistake my respect for weakness.** " With that, Byleth took her leave, shutting the door behind her with a quick flick of her tail.

Once she was out of earshot, and when he felt her presence continue to recede with the assistance of his seal, Seteth let out a breath he hadn't realized he was holding. "I don't." He answered to no one in particular, stomach growling now that the food was back under his nose. Grumbling, Seteth kicked himself for offering up his food to her. In his undistracted bliss, he'd neglected to get her a portion. He wanted her active and alert for the evening patrols, but that did mean that Seteth would need to sneak into the dining hall before bed to swipe some bread or fruit.

Or... perhaps not?

Seteth pulled the remaining food from the basket, shocked at the perfectly halved portions that remained. His surprise must’ve broadcasted through the bond because he could almost detect a sense of smug satisfaction on the other end, but he couldn’t quite tell.

The Ashen Demon was full of surprises.

  
  


**Notes for the Chapter:**

> Thank you so much for reading <3 
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	7. Audacity

**Summary for the Chapter:**

> Byleth is allowed to let loose. 
> 
> She does so explosively.
> 
> Seteth learns how to apologize.

Finally, Seteth had given her something to do. Byleth ignored the implications of being Seteth’s ‘attack dog’ and set out to track down her prey, stalking down the long corridors like a wolf eyeing sheep. The end of the moon was rapidly approaching, so it was only natural that she’d be given a task fit for the nature of her 'servitude.' Taking out the coward’s reinforcements would provide her the battle she craved while taking down the knight itself would be a significant victory enough. Steal the knight’s heart, and she could kill three birds with one stone. Seteth wouldn’t approve, but if he was troubled enough to send Byleth after this individual, then he genuinely didn’t care what happened to them. 

_Time to show him what I'm capable of._ She thought with a smirk, tucking to the shadows cast from the high, decorative arches. What she’d said to Seteth was only half a lie: she did know how to get around the Monastery, especially in the dark. When she didn’t want to deal with the student’s stares, it made for quite the entertaining game to slip by practically unnoticed. How little regard they had for their surroundings. Depending on how long this knight had been skulking about, she hoped he felt the same false sense of security. 

The last thing they’d be expecting on these holy grounds was a Demon, let alone _her_. 

Byleth lifted her nose to inhale, mouth opening slightly to taste the scents for anything that felt out of place. If the students were being targeted, it would be prudent to look around the dormitories. All of the students should have been in bed by now, so anything walking around was subject to intense scrutiny. The game of cat and mouse soon began once Byleth climbed up a pillar to crouch next to a gargoyle, ready to stake-out. 

She didn’t have to wait long. 

The sounds of an individual walking as silently as possible across the cobblestone hallways caught her attention, practiced assassin-like behavior, keeping them close to the walls and in the shadows. Were Byleth a human, he would have remained undetected, but the soft hairs in her ears vibrated with his careful steps, and her piercing eyes helped her sift through the shadows and darkness. She could see him clearly — messy brown hair, decently athletic build. Judging by the metallic tang to his scent, he carried two, maybe three, weapons. 

The most well-trained guard dogs only needed to bare their fangs once; he was overcompensating. It was time for a lesson in intimidation. 

Byleth hopped down from the gargoyle’s platform with ease, gripping her legs and claws against a pillar. Her sharp nails sunk into the stone, holding her suspended while her tail hung in the shadows below. The man paused, suspicious, but eventually continued moving as he inspected the nameplates outside of each door. When he was within a suitable distance, Byleth dropped down in front of him, a hand immediately over his mouth. She lowered her lips to his ear, whispering softly. “ **I’m going to let you run for a second because I’m not about to do this in front of the children’s rooms. I suggest-** ” Her tail pointed in the direction of the Professor’s quarter building. “ **-you run that way.** ” 

The man’s eyes were as wide as saucers, his shaking hands reaching for a weapon at his side. Byleth lifted her free hand, holding the sword and dagger between two deft fingers. All that remained was the dagger in his boot, but he didn’t seem to remember it there. “ **One… Two…** ” His fear scent was overwhelming and tantalizing. She hoped he gave her a good chase. “ **Three.** ” Her fingers let go of his mouth, and he immediately ran in her suggested direction. No longer worried about sound, his heavily thudding footsteps echoed along the stonework as she cracked her neck to each side. The wolf was ready for the chase. “ **Delicious.** ” 

Byleth immediately burst into action, dropping to all fours as her breath came out in ragged wisps in the cold, night air. He frequently checked over his shoulder for her, the sight of Byleth approaching inciting sheer terror, though he dared not yell into the night. At least this way, he held a minor chance of escaping? 

Unlikely. 

When he looked over his shoulder again, Byleth was gone. Confusion clouded his senses, making his decision making sloppy. When he continued forward towards what little bit of wall remained broken at the edge of the Eastern Monastery, Byleth jumped down from a roof she’d been running alongside, flattening him to the ground with a pained cry. Favoring the pinning technique Seteth used on her, Byleth chuckled as the man squirmed under her. How she missed having the upper hand in a fight.

“ **For a dark knight, I expected more of a fight. You seem a mere assassin. Do humans just… give out titles?** ” She teased, drinking in his fear like an ale. It was undoubtedly as intoxicating as one. 

The man’s lips trembled as he attempted to form words. “N-N-No… I’m not the k-knight, just hired to h-help him find the girl… _oh please don’t kill me, please, please-_ ” 

“ **Shut up.** ” Her tail thudded against his shin, causing him to gasp out a strained apology. “ **What do you mean, girl? What girl?** ” 

“I c-can’t tell y-you, he’ll k-k-kill me if I do!” The mousey squeaks of fear were now becoming tiresome as the terrified assassin under her writhed — what a wasted set of good muscles on such a coward. At least the Priest had the bravery and the looks, even if his personality didn’t match what she was looking for. 

All of his blatherings sent a ripple of fury through her. “ **I’m going to kill you if you** ** _don’t_** **tell me. I suggest you start talking before I spill your insides and see if they have any answers for me instead.** ” 

\---

As much as he hated to admit it, knowing that Byleth was currently patrolling the Monastery grounds made Seteth feel a bit better about their problem. Demons had their uses and specialties, so as long as he kept playing to Byleth’s strengths, then he could use her to help make the Monastery a safe place. He’d been asleep for a few hours, locked in a content dream about writing when he heard a heavy thud at his closed window. Before he could react, Byleth was shoving someone through it, her wings folding so that she could follow inside. 

Immediately awake, Seteth sat up in attention, senses on high alert as Byleth’s clawed fingers shoved the man forward. “ **Tell him what you told me.** ” Her eyes flicked up to Seteth’s, cold and stony like the first day he’d met her. “ **You want answers? He’s got some for you. Help me figure out who this girl is so we can watch her.** **If you had an inkling that a specific student was being targeted, perhaps you should have** ** _told_** **me, Priest!** ” 

_Why is she mad at me_? Seteth slipped out of his covers, standing to light a few candles in his room with a touch of magic. The assassin before him, all but driven to hysterics from Byleth no doubt, shook and trembled in the shadow of the Demon beside him. “I… am working with the k-k-knight to get a girl… she’s not a st-st-student, so we’re trying to find-” 

“ **Spit it out! We don’t have all night. I have a job to do, so I’m going to fucking do it.** ” She snarled, tail whipping to the side with impatience. Seteth had to control his own emotions, lest hers fueled his own. There was something about this that made Seteth’s blood run cold, a sentiment not lost on the Demon as she watched both men in the room. _We’d been doing so well. There’s no way they could have found out..._

“S-Sorry! She has the b-b-blood of the Goddess, presumably. We don’t know where the A-Archbishop is keeping her…” 

Seteth’s heart sank as he immediately grabbed for a shirt, not bothering to grab the long robes that kept him conservatively covered. “Knock him out, tie him up, do something. We need to get to her.” 

“ **So there is a specific girl here? Fuck, Priest, had I known-** ” 

“I know! I know!” Seteth hissed, messy fingers fumbling to open the door that led to the stairwell. “Goddess protect her, Goddess give me speed, they’re after Flayn.” 

The sheer _panic_ that Byleth could feel from Seteth was agonizing. She hoped she never felt it herself. Whoever this child was held great importance to the Priest, and while she couldn’t say she _understood_ , his emotions were enough to give her a taste. “ **Goddess can’t give you that right now, but I can.** ” With a swift swipe of her claws, Byleth grabbed Seteth in her arms. As they passed the assassin, the Demon’s tail slammed into the back of his head, laying him out cold on his stomach. Pleased with herself, Byleth hopped out the window with the Priest, wings opening to catch the air.

\---

Seteth’s trembling hands held onto Byleth’s arms as he all but white-knuckled her, afraid of falling. He was used to riding a Wyvern on it’s back, not being dangled from a Demon’s grip over the Monastery as he guided her to Flayn’s quarters. He _knew_ he should have denied her staying close to the students. He _knew_ it, and yet he agreed to it so Flayn could be closer to the kids her age. What had been an attempt to help her feel more included and fit in had been a horrible mistake, and now, if the dark knight had her, Seteth did not know what he would do. “Please hurry.” The only words he could manage. Byleth spared him the sass and did as she was told, tucking in her wings slightly so that they dove a little quicker. 

“There. This building.” The way Seteth’s voice shook rubbed Byleth the wrong way. This was the first human in a thousand years that had earned her respect, and he had been reduced to a puddle of anxiety over the cowardly actions of this knight? They could open the door to find Flayn, safe and sound. He was getting worked up over the hypotheticals, the excess fear spilling over into their bond. It took all of her concentration not to let it cloud her senses. 

“ **Okay, but fine, you didn’t bring a weapon, so take the rats.** **I’ll go in first since you’re not dressed for battle. If you die, I’m stuck going back so you can’t get hurt.** ” She growled, shoving one of the swords she’d taken from the mousey assassin into his hands. Her wings folded back into her skin, phasing through her clothes with a bit of magic. She utilized the distraction to shoulder in front of Seteth. The smell in the corridor was familiar. Sweet. _Pretty_. 

Fuck. 

Using her nose to suss out which door, Byleth immediately kicked under the lock, forcing it open. Seteth rushed past her, willing all of the lights inside to life with a surge of magic. The bedsheets were tousled, all her things disheveled while a bookshelf haphazardly leaned across the bed. Flayn's hair clips were scattered across the ground like caltrops. 

“Flayn, _no_ !” The Priest looked around the entire room, frantic eyes searching for the young girl in question as if it were about to be revealed that this was a sick prank. Byleth didn’t have to search too hard into Seteth’s feelings to know that, while the gnawing in his belly hoped for this to be fake, this was very, _very_ real. 

The connection was made almost instantly, now that Byleth could compare the two scents to one another. “ **She’s your daughter. The one with the blood of the Goddess is your daughter.** ” Seteth had reached her bed at this point, falling to his knees beside it, hands gripping the sheets with desperation. His head nodded weakly. How different this Seteth looked and felt. The once-proud Priest, who’d loomed over her in battle with a body spattered with both of their blood, now reduced to a crumpled heap next to a child’s bed. She had no younglings of her own, and could only feel an ounce of the despair in his heart through the bond. 

Even that ounce threatened to drown her. 

“ **They couldn’t have gotten far.** ” Snatching one of the hairclips, Byleth lifted it to her nose to catch Flayn’s scent. Without so much as another word, The Ashen Demon spun on a heel and walked outside to track her down. Tears threatened to spill over onto Seteth’s cheeks, but he couldn’t will himself to move, too wrapped up in the worries of losing Flayn to muster even a step. By the time he managed to stand and look outside the room, Byleth was gone.

\---

The girl with the pastries was his daughter. 

The fucking girl the pastries was Seteth’s daughter. Of course fate would intertwine them as such. 

_Focus, Byleth. Focus._ Byleth lifted the clip to her nose and inhaled once again. She couldn’t have gotten that far, so the scent would be fresh. The hair clip smelled of Flayn without the sickly sweet aroma of chocolate. The scent she should’ve picked up on earlier today. Fuck. 

The weak wisps of Flayn’s smell tugged at her nose-ring, tainted with the scent of her fear as well. A Demonic presence festered at it as well, causing The Ashen Demon a bit of alarm. Another Summon? Here? It led further past the garden, towards the Knight’s Quarters. All of the metal would make it difficult to smell past, the sharp smells of training and weapons all but assaulting her senses. 

She’d make sure to assault the knight when she was through. The doors were not locked, one recently jarred open with a heavy kick. It didn’t take much power to do so, but there was no room for underestimating this entity when it had Flayn. The only kind face she’d seen that had absolutely _nothing_ to do with her. Claude was kind out of fear. Seteth was… kind(?) out of duty and necessity. Flayn had been kind because she _was_ kind. The thought was foreign.

Another door forced open.

At least it was making it easy for her. 

Byleth pushed into a shared room, immediately stepping over the prone figure of a fallen Professor. The woman’s shoulders were still rising and falling with short breaths, so she’d be fine. Byleth had other things to worry about, like why the trail ended in this room. Surely the well-endowed professor she’d seen flitting back and forth down the hallways was not the culprit: she didn’t seem like she’d be able to fight her way out of a paper bag. Too flimsy, too exposed. Byleth preferred her skin covered and protected, muscles hardened for battle.

No, this woman was innocent. 

The scent led up to the wall, where a bit of the wall itself seemed… ajar? Upon further inspection, her claw slid under the inconsistency, opening a secret door. Immediately the scent returned, fresh and strong, though mixed with mildew and old, stale water. “ **Found you.** ”

\---

Rage bubbled in Byleth’s chest as she descended the damp staircase she'd found, a hidden passage tucked on the far wall. Flayn’s fear scent was just up ahead - how careless she’d been not to have noticed their relationship before now. Perhaps the bond was strengthening the emotions between them, causing it to bleed over into Byleth’s own psyche, but whatever the explanation: She was _livid._ No one should be reduced to such a point by petty, underhanded tactics. The utter defeat was something that was to be served one on one. If she had a human heart, it would have been breaking for her contract holder.

The staircase led her to a room that opened up into a vast underground passage, marked in the center by an elevated podium. Byleth’s eyes honed in on the unconscious girl set atop of it immediately. Flayn was sprawled at the feet of an imposing figure clad in heavy, black armor. Spikes jutted from pauldrons and bracers alike, stained with dried blood and ichor, and upon hearing Byleth enter, the warrior turned to face her. “ ** _I did not expect to be found so quickly. You are rather resourceful, Ashen Demon._ **” Byleth refused to give the man any satisfaction from her confusion, masking it beneath her stony visage. 

“ **I did not expect to see another Summon here. I should’ve suspected it was you at their description. What are you doing, Death Knight?** ” Byleth placed a hand on her hip expectantly, the tip of her tail flicking with irritation. The man removed his studded helmet, revealing another monstrous Demon, much like Byleth. He didn’t have much skin on his face and had very pronounced skeletal features. While this particular individual wasn't a General, from what she remembered, the knight had ambitions to become one.

“ ** _I was Summoned for a few tasks involving this young girl._** ” His foot raised to step on Flayn's side as if she were a fresh kill, posing for a painting. “ ** _Fetching her was part of a Command. You know how humans can get._ **” 

Byleth physically bristled, tail lashing at his action. Her sharp eyes narrowed at his foot before returning to his stoic face. “ **Too bad. The girl is mine. I will not let you take her.** ” Scales began to cover her skin, and her back cracked as she hunched slightly. 

The skeletal Demon’s features remained emotionless as Byleth transformed. " _ **I**_ ** _t’s not like The Ashen Demon to get possessive. Surely you of all Demons can see this as a secured victory._ **” Her bones groaned in protest, crackling as they reformed. The sick sounds echoed off the stone walls of the underground passage, mingling with the whispers of the mercenaries the fellow Summon had brought with him. 

“ **It is unlike Lesser Demon trash to speak so brazenly to someone superior. Victory is between you and an opponent. Tell me, did her razor-sharp claws slice the flesh from your bones as you fought? Did her magic sear you to your core? Such a** **_valiant_** **victory. This is beneath us, and** ** _ngh-_ ** ” Her neck snapped from side to side as she dropped to all fours, claws lengthening as the Demon's body changed. Grew. “ **-you know it.** ” 

The Death Knight’s hollow eyes watched Byleth’s body wrack and grow. “ ** _Such emotion. It would normally be a treat to see the Legendary Ashen Demon in action, even more so to cross blades with her, but I do not know who this is before me. I hardly recognize you anymore. What has happened to you?_ **”

His words stung, frustration fueling the fires of war within her. All his words reminded her of was the mirror dream. She’d been lucky enough not to have it again, but… he was right to an extent. Why was she so protective of this young girl? Was it because she owed her father a debt? Was it because she was a kind face in a sea of suspicion? Why was she _feeling_ anything at all, besides the three identities of herself that kept her going? Was it the seal on her chest?

_Was she changing? Mentally morphing into something new?_

The questions melted into the back of her mind. The primal urge to take the gift of massacre Seteth had allowed her took over as her true form finalized. Staring down The Death Knight in the winding corridor lumbered a living, breathing dragon. 

The Ashen Demon herself snarled, lips tight over the jagged set of teeth she bared. Sharp spines rode up the bridge of her nose, disappearing into a thick mane of black fur that trailed down her neck and to her chest. Her body was large, large enough to struggle to maneuver over the walls that separated her and the other Demon. 

Walls that separated her from Flayn, the target. So be it, she would leave no corner unturned, no body unflayed. 

“ **I don’t think you want to stay and find out, Death Knight. Back away from the girl. I am protecting this ground, and I will not have a Lesser spawn keep me from my duties.** ” The Death Knight’s face revealed no emotion, though she knew hers did. She could smell his fear scent, driving her instincts wild with the bloodlust she craved. “ **A contract stipulation will be fulfilled tonight, but it will not be yours. This is your last chance.** ” 

“ ** _The Ashen Demon would never allow an enemy to truly flee. She would let them think they had a chance before reveling in dismay as she chased them down. I will slay you and take your title, and use my ascension to break my own contract."_** The skeletal grip on his scythe tightened in anticipation — bold words from a nervous target.

The dragon’s chest rumbled with amusement, practically purring at his defiance. “ **Then you will perish.”** Byleth turned her massive body towards the first hallway, rearing her head back as she inhaled. The beasts giant lungs filled to capacity before she stared down her nose at the Mercenaries before her. As she exhaled, black fire poured from her gaping maw, incinerating everything in its path. The smell of burning flesh began to fill the air as nothing remained of the humans but ash. The Ashen Demon, indeed.

“ _ **T**_ ** _o arms!_** _”_ The Death Knight roared as he charged forward, leaving Flayn where she lay. His troops, the Mercenaries, exchanged glances before dropping their weapons and turning to flee. “ ** _Human cowards..!_ **” 

“ **You did not face your death with courage, humans. Be baptized in flame, so that you may return a nobler soul.** ” Byleth let out another stream of fire, dark tendrils of flame engulfing them as they ran. All before her would turn to ash until she was satiated. Demons were summoned to this plane for a reason: sheer, destructive power. The Ashen Demon was no exception. _Do not mistake my respect for you as weakness, Seteth. I am power incarnate, even if I allow you to direct the flames._ “ **I’m afraid I cannot gift you with such words, Death Knight. Take pride in your defeat, however, and know that you will reincarnate into something with a bit more respect.** ” 

Byleth continued to barrel through the opposition, crushing and burning all she could reach. A volley of arrows lodged the sharp weapons underneath a few of her scales, distracting her enough for one or two brave souls to slice at her forelegs. These were problems for a different time. For now? Kill and protect. Those were her orders. 

After dispatching the archers and the last of the mercenaries, It didn’t take long for the giant dragon to cover the distance between herself and The Death Knight. His scythe raised to engage. “ **This goes far beyond contracts, Death Knight.** ” Her foreleg stomped the ground, the slow trickle of blood down her foreleg beginning to pool at the ground. “ **You insulted me. You took from my contract holder, and by extension, me. You challenged my authority as protector of this place, and come at me to take my title. All of this I could** **_possibly_ ** **forgive.** ” She growled, large neck snaking to the side as it lowered. “ **But, you had the** **_audacity_ ** **to place your filthy feet on her, and that is unforgivable.** ”

The Death Knight's scoff lingered for a few seconds. “ ** _Why do you care so much for her, or for any of the souls that wander above us? They will continue to hate our existence, content to live in their lies while we suffer. When your usefulness runs dry, you will be sent back. Not a single being cares about you here.”_ ** Death Knight sneered, staring at the dragon across from him. Byleth thought back, sifting through memories of the past month. The scent of chocolate that clung to Flayn’s clothes, and the phantom pain of a split lip, healed with a gentle touch. 

The growl that rumbled in The Ashen Demon’s chest intensified, beginning to echo off the ancient chamber walls. The Death Knight charged. Byleth remained still. “ **I would tell you you’re wrong-** ” Her voice hissed, flames licking at the back of her throat. “ **-But it would fall on the ears of a dead Demon. I owe you nothing. No explanation, and certainly no title. I may be changing, but I do know what stares back at me in the mirror.** ” The scythe drew near, glowing with a red haze. “ **Something far better than you.** ” As The Death Knight came into range-

-Byleth’s jaws clamped down around his side.

With a mighty shake of her head, she slammed The Death Knight into the wall nearest her before throwing the bleeding body across the chamber. His scythe lodged in her chin, wedged haphazardly where The Death Knight had tried to inflict any injury. He landed unceremoniously, skidding to a halt once his body ran into the far wall. Byleth’s tail curled protectively around the dias Flayn’s unconscious body rested on while a front claw pried the weapon off of her face. “ **Tell me who Summoned you, and why did they make the beasts attack?** ” The scythe snapped in half in her claws, falling to the ground in pieces.

The Death Knight struggled to his feet, gritting his teeth as he fought to stay upright. “ ** _You are mistaken if you think I will tell you anything, you Ashen fraud. Take comfort in knowing you were denied the victory you so desperately crave.”_ **

“ **Dammit, Death Knight! Don’t you da-** ” Byleth warned, opening the wings on her back in an attempt to make her look larger than she was, approaching the Demon with intimidating intent. The Death Knight’s stoic expression didn’t change as magic enveloped him. One moment he was there, but the next… he was gone. The teleportation spell swept him away, much to The Ashen Demon’s ire. Her roar of frustration rattled the halls, tail slamming into the ground with fury. There was no point getting too worked up; the battle was finished. 

But The Death Knight was wrong. Not all victories involved death, it seemed. 

As Byleth’s head turned back to appraise Flayn, her breathing slowed, and her shoulders relaxed. She’d gotten what she wanted out of the night as the brand on her chest burned bright. Seteth’s portion had been fulfilled: The Ashen Demon’s battle quota had been met for now. Even though The Death Knight got away, there was more than enough ash scattered across the ground, an adequate offering of destruction for the dragon. Moving forward, however… there was no way she was fitting through the stairway like this. 

“ ** _Ngh…_** ” Her body began to change, shuddering as muscles stretched and folded. Bones cracked, and she took sharp, pained breaths as her body worked to reset. She could take this form as often as she liked, but the repercussions were just as destructive as the form. No power should be gifted idly, and Demon Generals were excellent examples of that. Byleth had learned to chase victory without her full form, saving it only for the most important or flashiest of moments, but nothing killed morale like a _dragon_. 

Nothing destroyed underground chambers like a dragon, either. As her body continued to shift, her eyes focused on the room around her. Anything to divert her thoughts from the pain. Scorch marks from her fire stained the ground and walls alike, while her nails had gouged scratches and chunks out of the stone floor itself. And the _ash_. The room was covered in it. With each movement she made, every wingbeat as her body struggled, the ash scattered into the air. By the time Byleth had achieved a more suitable form for exiting the room, a half form that slowly receded, ashes all but fell from the ceiling as they clung to the air. When she breathed it in… it smelled of smoke and victory.

Such hunger… Her eyes looked past Flayn to some of the bodies she hadn’t incinerated, a few battered by her tail or crushed beneath her massive legs. No… she needed to get Flayn out safe.

Byleth crouched to pick the child up, lifting her off of the podium. Her skin was covered in a fine layer of the ashy remnants of her battle, clothes unfortunately ruined. Despite the fact, Byleth doubted the girl truly minded, given that she would wake up safe. “ **All this death for such a tiny package.** ” She murmured, a raspy growl from both the snarling and fire-breathing. Her legs wobbled with exhaustion as Byleth began to walk back up the steps towards the Knight’s Quarters. “ **And yet, I have no doubt he will be pleased.** ”

Why did Byleth care? Why did Byleth care about _any_ of this? There was truth riddled in The Death Knight’s words: As soon as she wasn’t of further use, the contract would be completed, and she’d return home. The fact that a Lesser Demon had called her out for the changes she couldn’t deny were underway was troubling, but what she felt didn’t make her feel _weak_. Her monstrous face lowered to look at Flayn in her arms, reptilian snout and eyes appraising her, making sure she had no wounds. Whatever feelings were developing, whatever human-like bonds were forming, they made her feel _strong_. Flayn, Claude… even Seteth. Her wings rustled against her back, folding close so she could fit through the doorway. With each step, she took a bit of ash wafted off of her body until a line of ashen footprints noted her presence. A line that was beelining straight for Seteth’s chambers. 

Judging by the way the hazy sunlight was just beginning to peek over the horizon, it was still early in the morning. 

Another step, another footprint. 

Another step, another footprint. 

The first student that saw her in the early morning light immediately stiffened at her appearance, more draconic than human. However, as she neared the building where Seteth was likely waking up, the features began to subside. The thick mane that hung from her head and wrapped around her chest began to disappear, scales retreating into her skin. The blood that ran down her chin from the scythe's wound had nothing to soak in, beginning to slip down her back and beneath her torn shirt. Her only saving grace for not being attacked, Byleth concluded, was that she was carrying Flayn in her arms. 

More students gathered as she marched slowly, cold eyes facing forward. “ ** _Ngh!_ **” She paused, bracing herself as the snout began to recede into her face. Monstrous fangs shortened back to her normal teeth, and even her nose ring shrunk in size to fit her usual appearance. Once the pain had subsided, Byleth continued. 

Another step, another footprint.

The whispers of the prying eyes that judged didn’t bother her. They were not unlike others she’d heard. Let them theorize. The truth would come out eventually, and then she dared them to speak in their hushed, jeering tones. The new emotions she was experiencing did not change everything about her: she was still a Demon, and she always wanted the proper respect. The Death Knight found out the hard way. Let them do the same. 

How would he react when he saw Flayn? The Ashen Demon was hardly the subservient type, but something from their spar had stuck with her. Seteth had longed for acknowledgment, albeit for Byleth’s respect and willing cooperation. The nagging thought stung like the broken arrows stuck in her back. Was she fighting for his acknowledgment and respect too? He would no doubt be relieved to see his daughter safe and sound, but was there any part of him that didn’t treat her like the demonic object she was on this plane? Would that part be happy she’d returned victorious and relatively unscathed? 

Another step, another footprint. 

Byleth kicked open the door that led to the Professor’s quarters, angling sideways to enter with the unconscious Flayn. Another spasm of pain coursed through her body as the final wave of scales disappeared beneath her ash-covered skin. Her tail thudded against the wall as it thrashed before the waves of agony subsided. _Almost there._

Everything in her body pleaded for rest. Rest from the physical exertion of molding into the real beast she was, and rest from the emotional gymnastics that came with the seal on her chest. Flayn was easy to carry compared to the burden of feelings. 

Another step, another footprint. 

Ash dusted the ground as she rounded the corner for the final staircase. The scent of Seteth could be detected through the smoke that dominated her senses. He was clean, collected, and unmarked. Everything she was not. Did he mind?

Her foot kicked at the door, jarring it open with force. 

Seteth flinched as he turned to the door, robes half-buttoned in front of the mirror. The last of her transformation completed itself, wings folding into the skin of her back through the giant rip in her loose shirt. Byleth continued forward, each step shaking more ash from her clothing onto the ground, but Seteth didn’t seem to notice. His gaze had initially crossed Byleth, startled by the blood that trailed down her neck, but immediately lowered to Flayn, safe and unharmed in the Demon's arms. The sound that escaped his mouth was unlike anything that the Demon had heard before, sheer relief in vocal form. 

It made her feel warm.

“ _Goddess, Flayn…_ ” He reached for her, but Byleth continued walking past him, only stopping once she arrived at Seteth’s bedside. The worried father bounced off of her shoulder, looking down at the layer of ash that now marked his clothing. Careful not to jostle her, The Demon deposited her onto the soft surface, covers immediately stained with the ash that settled on Flayn’s skin and clothes. As Byleth pulled away, Seteth took her place to examine his daughter. Reverent, whispered prayers poured from his lips as his hand cupped Flayn’s cheek, tears brimming in the Priest’s eyes. They spilled over almost as quickly as they’d formed, a strained choke in his throat as he tried not to sob. The dextrous fingers that were wrapped for battle not a month ago were the same ones that cradled the young girl’s tiny hand, holding it in place for Seteth to press his forehead against. By the way his shoulders trembled Byleth knew he was crying. 

“ _Thank you._ ” 

His whisper was muffled by the bed, hardly perceptible if it weren’t for Byleth’s heightened senses. 

“ _Thank you, thank you, thank you._ ” The words were almost a rhythm, whispered as reverently as his prayers. With each gesture of gratitude, her head felt lighter. Exhaustion willed her to sleep at any moment, but curiosity had compelled her to stay. Now that they were reunited, her job was done. There was no need for overstaying her welcome in such a tender scene. Her fingers brushed against the brand on her chest in acknowledgment. No words needed to be said: Byleth was sure he felt the gesture. 

She turned on a heel and slipped into the washroom, climbing into the bathtub. Her tail curled around her as best it could, her head curling in as though she were a napping feline. The broken arrows scraped against the tub, but she didn't feel them. The last thing she heard was Seteth’s words echoing through her mind. The apology, the acknowledgment, the sheer relief upon seeing Flayn… 

The brand on her chest illuminated the dark washroom as another contract was fulfilled. _Victory_.

The Ashen Demon finally slept.

**Notes for the Chapter:**

> Gosh, thank you guys so much for reading so far. I really appreciate it. I'm really only still writing fanfic and posting stuff because the fandom is awesome and ya'll are stellar. Thoughts/critique/theorycrafting always welcome.
> 
> Thank you so much for reading <3 
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	8. Healing

**Summary for the Chapter:**

> Flayn finds healing with a friend. 
> 
> Byleth finds healing with a friend(?).
> 
> Seteth is Seteth and struggles with all of this.

It had been three hours, twenty-seven minutes, and fifteen seconds since Byleth had brought Flayn back. She was sleeping peacefully, hand in Seteth’s as he sat by the bedside anxiously. Classes had been canceled for the day so that Seteth could attend to Flayn's needs, and the sleeping Demon, who was currently snoring in the bathtub. The sound wasn’t enough to wake Flayn... but he had closed the door to be safe. 

There was a lot that needed to be done today. Flayn’s bedroom needed to be moved, the place where she’d been taken to needed to be investigated, Byleth needed to be healed (he could have sworn he saw _arrows_ sticking out of her?) and none of it would be remotely touched until he was sure that his daughter was okay. The Monastery would understand. 

He’d almost lost her. He’d practically lost Flayn. 

_Stop it._ He chastised himself, attempting to rid his head of the troubling thoughts. At this point, all that mattered is that she was safe. Thankfully, he didn’t have to linger on unpleasant feelings for long. The daughter in question began to stir, tiny breaths suddenly increasing with fear.

“..!” Flayn’s eyes fluttered open as she sat straight up, face full of confusion as she tried to gather her bearings. Her hand tightened around Seteth’s as she whipped her head to face him, bottom lip trembling. Before he could utter any words of reassurance or comfort, Flayn threw her arms around him, smearing him with ash and tears as she gripped tightly. “Oh, Father, I was so… _hic_! ….scared…” 

“Ssssh, Flayn, it is okay, you’re safe now.” Seteth readjusted so he could pull her into his lap, wrapping her in his arms in a comforting gesture. Flayn didn’t fight, nuzzling her face into his chest as she whimpered. 

“They broke down my door, a-and made a mess out of my room… I’m so sorry…” The young girl’s murmurs were almost unintelligible, but the moment she apologized, Seteth squeezed her harder. 

He made sure to maneuver his face to be in front of hers. Perhaps if she saw him say it, she would believe it. “Flayn, you have _absolutely no reason to apologize_. Darling, I need you to listen to me when I say this. You have _no_ reason to apologize. You did nothing wrong. If anyone should apologize, it is me. Flayn, I am _so sorry_ that this happened. I’m so sorry.” His voice cracked a few times, running his hand through Flayn’s messy hair. She murmured some reply, but he couldn’t understand. “What was that, dear?”

The girl ran a dirty hand across her face, wiping her nose before sniffling loudly. “I got saved, though...”

Seteth nodded, tucking a loose curl back behind her ear. “And I am so delighted that you did. We looked everywhere, but I am happy Byleth found you.” 

Her eyes flicked around the room, looking for the Demon in question. “Where is she? I don’t want that other Demon to come back…” The grip around Seteth tightened ever-so-slightly. _Other Demon?!_ _Just what happened down there?_

“She is just in there.” He pointed with his foot towards the bathroom door. “She is sleeping, but if you are scared I can send her elsewhere for now. It would be understandable, and I doubt she would be ups-”  
  
“What? No, I want her to be close. What if the big knight comes back? Please do not send her away. I gave her chocolate.” Flayn whispered the last part as if it were a secret between the two of them. 

The Priest blinked, confused, but petted her tousled locks. “I will not send her away then. I am… glad you feel safe around her.” The bubbling ichor of jealousy wrapped around his heart, sad he could not be the one to make her feel safer in her hour of need, but Seteth swallowed the disgusting thoughts as quickly as they’d surfaced, ashamed of himself. “I’m just so glad you’re safe. There is much to talk about, but it does not have to be today. I am moving your room closer to me-” 

“- and Byleth?”

“... yes, and Byleth.” 

Seteth expected resistance; Flayn wanted to stay near the students, who were closer to her in age. It had been something they’d gone back and forth about for a while, but eventually, Seteth cracked and let her stay where she was. Moving Flayn back near him was going to be difficult.

“... Okay.” He looked down at his daughter with surprise. She met his gaze with glassy eyes, cheeks red from silently sniffling against him. “I do not want it to happen again. Being close to you and Byleth at night would make me feel a lot better. I… can see the students during the day, right?”

“Of course. I will get started on the move right away. Why don’t we get your things and get you cleaned up? I bet I still have some of the Crescent-Moon Tea left over. How does that sound?” A careful finger slid down her forehead to playfully boop her nose affectionately. Flayn giggled despite herself, lips turning up into a genuine smile despite the traumatic evening prior. 

“I would like that a lot.” 

\---

It didn’t take long for Flayn to get settled in her new room, just down the stairs from Seteth. She was freshly cleaned and happily sipping on a cup of her favorite tea when Seteth leaned against the doorframe to check on her. The number of stairs it took to get to her room already made her feel better as she curled up in a large, fluffy blanket. “Is this room suitable?” He inquired, raising an eyebrow at just how quickly she’d managed to decorate it.

Her face shifted in her giant blanket cocoon, nodding. “It is. If… if I get scared while you are doing work, can I go back into your room?” 

“Of course. Whatever will help.” 

“I think some fruit sorbet would also really help. A lot of sorbet.” She grinned cheekily. _It looks_ _like someone is feeling better._

Seteth ran a hand through his hair. “Perhaps I could find some on my way back.” _She went through a lot._ Granted, Seteth had no idea just _what_ she went through, questioning Byleth was on the list at some point, but it was a good enough reason to relax upon his rules. _Somewhat_. “If you get scared, you can go back upstairs. I’m going to go investigate so that this does not happen again, but I will be back soon.” 

The cocoon shuffled slightly as Flayn’s tiny hand stuck out the hole for her face. A single pinky was extended. “Promise?”

Careful not to step on any of her belongings, Seteth strode inside and locked his pinky with hers, leaning forward to kiss it gently. “I am a man of my word.” 

\---

There were many things Seteth did not know about the world. It’s vastness, for one, was something he would never fully wrap his head around. How the Goddess had come into creation was another, a hot debate topic for many who have led the church. However, these topics were unrelated as he tried to figure out another mystery: what in all of Fodlan could have obliterated this underground chamber to such an extent? Both he and the cowardly assassin in Monastery custody stood in awe at the massive scorch marks, piles of ash, crushed bodies, and the large scrapes in stone from giant claws. 

After a few moments to admire the ‘handiwork,’ Seteth cleared his throat and spoke to the knights behind him. The firm grip he held on the assassin’s shoulder loosened as the Priest stepped forward. “Take him away. I am going to see what traces of magic I can find here.” Seteth removed his outer robes, draping them across the cleanest sconce he could find. The room was still flooded with ash, no doubt from whatever magic Byleth had conjured. 

The better question was _how_. 

The Knights of Seiros complied, nodding their heads before nudging the assassin back up the steps. “Hey, wait, wait! You’re not gonna let that fucking Demon turn me into ash like that, are ya?!” He scrambled to get out of one of their firm grips, to no avail.

Seteth turned to glance over his shoulder, meeting the fighter’s frantic gaze with a cool one. “Perhaps you should tell the interrogator all that you know so that you do not find out the answer to that question.” The execution of the line was enough to shut the frenzied man up, immediately relaxing to not jostle the knights around him. The Priest took his silence as answer enough, returning his attention to the vast chamber before him. “Alright, chamber. Show me your secrets.” 

Magic flared at his fingertips, burning white-hot as he pressed them to the ground. It surged in front of him, like an ocean wave, crashing against the first wall it came to. The magic reformed into the visage of the beginning of Byleth’s casualties, the front hallway Mercenaries. They were frozen in time as a cascade of flames hurtled towards them. When the white magic tried to reform the image of Byleth, dark waves surged against the white, fizzling both sources out into the crisp air around them. Seteth stood, blinking. _Byleth…_ He surveyed the spot where his magic had failed before pushing ahead to look for more information. _Just what are you_?

With the assistance of magic, he had a better idea of what happened. While he couldn’t use it to get a look at what Byleth actually _did_ , the echoes of The Death Knight gave him a good look at the armor of the perpetrator, as well as his face. They’d had a conversation of some sort before they fought, The Death Knight somehow rocketed to the other side of the room before the trail went cold. To use teleportation magic in the heat of battle was no small feat. All in all, forty-three mercenaries were either squashed, incinerated, or battered to death. Their echoes were all silently screaming, faces twisted into grotesque masks of pain before they met their untimely end. Seteth had a few answers but eventually left with more questions. He would check on Flayn first before waking Byleth to heal and inquire. 

\---

“Flayn? I’m coming in.” He thought better than forcing his way into her room, afraid of startling her. When no answer came, he gently turned the knob and peeked inside. Her blanket cocoon and tea were still on the bed, but Flayn was not inside. The immediate fear that gripped his heart sent a chill down his spine, _not again, not again!_ Seteth all but stumbled up the stairs to his room, throwing the heavy door open with haphazard speed. It slammed into the wall stop, making a decent crash. Flayn was not on the bed, but the door to the bathroom was open. 

“ **She’s in here.** ” 

Byleth’s rough voice made his shoulders relax immediately, a sigh escaping his lips as he did his best to calm his rapid heart rate. “Ah, thank the Goddess. I’m coming in.”

“ **Please do. I am… confused.** ” _Confused?_ Mildly intrigued, Seteth rounded the corner and looked into the bathroom. Byleth was propped against the far wall of the tub, broken arrows jutting above the side like spikes. Flayn’s green curls were visible first, the young girl’s head leaned against Byleth’s side while a draconic tail wrapped around her, almost protectively. The tiny human’s hand clutched the scaled appendage, her content face lost to sleep. Byleth was careful not to touch her with her clawed fingers, hands clasped neatly in her own lap. 

Byleth met Seteth’s eyes, brows furrowing. “ **What is this feeling?** ”

There were a lot of feelings that Seteth had to sort through upon seeing this, but elected to pull up the chair from his bedside and ignore all of them for the time being. “I can attempt to help. What are you feeling?” 

The Ashen Demon’s gaze focused on Flayn. “ **She was kind, not in the same sense of obligation, like Claude or yourself. So, when I saw she’d been taken-** ” Her hand reached out to Seteth’s, dropping the hair clip she’d used to track Flayn gently into his open palm. “ **I was angry. That emotion I understand. However, when The Death Knight placed his foot on her like she was a fresh kill, I was furious. A step up from angry, but not unknown to me. But after The Death Knight escaped there was a feeling of relief. I wrote it off as such when I carried her out, but it continued to spread. I could feel it everywhere, from the tip of my tail to the curve of my horns. It burrowed deep into my marrow until I could not stand it. The warmth expanded, taking root like an ancient oak and I found myself ready to face another thousand armies for her.** ” The Demon lifted a hand, gingerly shifting a strand of hair from the sleeping child's face. Her hand shook, afraid of injuring Flayn. **“I think I am broken.** ” 

It too a moment for Seteth to formulate his reply. Byleth waited patiently, eager for a true definition and opinion. “I do not know how many hearts Demons have, but they are heavy burdens. That emotion sounds like love.” _Could_ Demons love? The thought vexed him as he leaned back in the chair, rolling the hair clip in his hand idly. The answer didn’t seem to satisfy Byleth, who wrinkled her nose. 

“ **Love? No, you are mistaken. I do not wish to take this child as an eventual mate.”**

Seteth choked on a cough, eyes wide as he struggled to remain calm amid the increasingly odd conversation they were having. Worried he would wake Flayn, he cleared his throat and took a very, very large deep breath. “No, Demon. There are… different types of love.” 

“ **Ridiculous. Human emotions are impossible. This seal is a curse. Are there twelve different types of hunger as well? Or seventeen different types of uncomfortable?** ” 

_No, though, I believe I am feeling at least seven of them._ “The love one feels for family, and the love one feels for, how did you put it- a mate-, is different. Do you have children of your own?” Perhaps if Byleth had a point of reference?

“ **Humans breed for love? Not for combining strengths for variable offspring?** ” 

Seteth was dumbfounded. “... Yes. We do. Do Demons not?!” 

Byleth smirked. “ **Of course we do, I needed to amuse myself before I felt too uncomfortable with this conversation.** ” Her chuckle brought a small smirk to his lips as well, despite himself. Where he would have felt one of the ten types of annoyance, he was amused instead. “ **But no, I do not have any offspring. No Demon has caught my eye. I could have some if I wanted. But with the threat of Summoning, and me no mate, they would be alone and quickly sought after. I am rather powerful.** ” 

The thought had never crossed Seteth’s mind that Demons were just… pulled from their lives to come to their world. It was his understanding that many of them craved it, but Byleth getting ‘lucky’ with the initial broken circle was probably rarer than he realized. What surprised him, even more, was the level of thought Byleth had put into it. “I… see. I did not consider that side of things. In, uh, any case, the emotions are different. You can feel a familial bond for Flayn, but it would feel different compared to the love for a mate.” 

“ **Hmph. Well.** ” Her furrowed brow relaxed a bit when she looked down at Flayn once again. “ **I suppose if I am to struggle, I am… content that it is for her.** ” She glared up at Seteth suddenly, eyes flaring with magic. “ **Don’t you** **_dare_ ** **tell anyone.** ” 

He held up his hands in front of him. “Your secret is safe with me. Is this the only emotion you were struggling with?”  
  
“ **Ugh. No. I feel wisps of yours, and I feel my own brought on from this obnoxious seal-** ” 

“Are you sure it is the seal? You can feel when my emotion bleeds into yours, but I can feel emotions that stem from you as well.”  
  
“ **Yes! Because of the seal! I never experienced anything like this before your magic.** ” 

Seteth tapped his chin thoughtfully. “Yes, but you have also not been in the human domain for quite some time, right? I cannot claim to know much about your realm - mind you, this is a conversational point I would like to come back to soon - but perhaps you just lived around the same routine and stimuli?” 

Byleth considered his words. “ **... We can indeed be creatures of routine. Work, Eat, Sleep-** ” 

“Pardon the interruption.” Seteth raised his hand to stop her. “You worked? As in, had a job?” 

Her ears flattened back, offended. “ **Do you think we just sat in an open field, twiddling our tails while we waited to be Summoned? Hellflame, you seriously have no idea about Demons, do you?** **_Yes_** **, I had a job. I am a master tactician. I have led armies longer than you have been alive, longer than anyone that draws breath on this plane has been alive.** ” 

Sufficiently chastised, the silence between the two lingered until Seteth eventually spoke. “You are correct. It appears we do not know much about your kind, despite our dusty tomes and lengthy recollections. Why is that?” 

“ **The winner writes history** **,** ” Byleth grumbled, looking down at her hands. “ **But I revel in work. I like to keep my hands busy and dirty. There is always a war to be won. Peace never holds long, even here in your space. There is no room for…** **_love_ ** **on the battlefield. I’ve seen what it does to the careless. It makes you make mistakes. Perhaps you are correct about the stimuli being different, but I will remain content in my limited emotional range in exchange for life, thank you.** ”

While she had a point, Seteth couldn't necessarily agree with her. Love was powerful but in the hands of the distracted… "I see. Perhaps we should not table the Demonology discussion any longer." Anything to get Seteth off of this topic. Helping the Demon suss out her emotions was okay, but coming to terms with his own was something he preferred to do in private. "I do think it would be best to return Flayn to her room now, though. We still have to get those out of your back." 

Her gaze soured as she tried to look over her shoulder at the arrows behind her, with no luck. " **Bah, rip them out and heal them up. It will take no time at all.** " Her tail slid off of Flayn, prying itself from her sleepy grip to rest on the floor of the tub. " **I agree; she deserves somewhere more comfortable. I am not known for my softness.** " 

Seteth shot her an amused look. "Says the Demon who was afraid to _touch_ her." The look he got in response was worth it as he bent down to scoop Flayn into his arms. "I will return in a moment." 

" **Yeah, yeah. Trip and fall down the stairs.** "

"I will be holding Flayn."

" **Bah! Fine. Don't.** " 

"Thank you."

\---

Byleth's back throbbed as she moved, positioning herself better for the arrows to be extracted once Seteth returned. _Love, what a ridiculous notion._ She cared for the girl, but why? Her thumbs slipped under the leather straps of the bits of armor she wore, gingerly removing it despite the groan of her muscles. Transforming was a pain, but it didn't bother Byleth as much as the worry she'd felt for the green-curled child. _If love was going to tear me down, I'd prefer it to be a man. At least I'd get something out of it._ As much as she repeated the thought in her head, it didn't erase the warm feeling from protecting Flayn in her darkest hour or keeping watch while she slept against her side, snuggling an ashy tail. _The Ashen Demon brought down by protective parental thoughts of a human child. I'd be the laughing stock of the Demon world._ And yet, she felt no embarrassment. _Let them laugh._ The Ashen Demon shied away from no challenge, even this emotional one. Not the warmth she felt for Flayn, and certainly not the creeping affection she was feeling for the Priest.

Physical attraction was there, yes. He was easy on her eyes, even more so after he'd beat her into mild submission on the second night of the contract. She was no stranger to being physically attracted to someone, but it was the _little_ things that caught her by surprise. The way he pushed his glasses up whenever he was focusing hard on a passage, or the way he lit up whenever he got into a conversation about Flayn. All of his words and movements were deliberate, something she could appreciate. He said what he meant and did not dance around truths. It made conversation with him easy. Sometimes, she even looked forward to it. The sinking suspicion that it was not just physical infatuation began to grow as she awaited his return. 

He was not gone long, returning to the chair to sit while Byleth finished slipping off the rest of her armor. She deposited the last elbow guard over the edge of the tub, hearing the metal rattle as it struck the floor. All that was in the way now was her shirt. "Flayn is resting again. I made sure to wrap her up nice and tight in her blankets."

" **Good. Poor youngling has been through a lot.** "

"On that, we can agree." He chuckled, noting the lack of armor and her back facing him. "I am going to work these out now. However, it would be easier if… your, uh, shirt-"

No. Byleth's ears flicked back in shock, pressed against the sides of her head with intense discontent. " **And fully expose myself, The Ashen Demon, General of King Jeralt The Blade Breaker, to the strongest human in this Monastery? Preposterous.** " 

He had expected this. Seteth cleared his throat as he worked towards the correct words. "It is true that I did not trust you. And I do not blame you for your distrust of me, but-" he sucked in a breath. "- I owe you. Beyond contracts, beyond stipulations. You took care of my daughter, and that speaks _worlds_ beyond bloodlines and planes. I could never, in my right mind, raise a hand against you again. Most of my distrust stems from attempting to keep her safe, but seeing her with you has helped your case." 

Blood roared in her ears as she debated a course of action in her head. Seteth never said anything he didn't mean, and she often teased him about his lack of trust, just as he did for her emotional struggles. It would be hypocritical of her to show a lack of confidence now, especially with how far they'd come since day one. "... **fine. I** **_trust_ ** **you.** " 

Her fingers hooked under the long-sleeved shirt she wore, attempting to pull it up over her head in one smooth motion. Seteth waited to help loop the shafts through the holes they'd created in the garment but flinched as Byleth's back wrenched. She couldn't lift her hands over a certain level, arrows catching in her muscles. " ** _Ngh_ **…" 

"Let me help you." Seteth stepped forward, hooking his hands under the hem of her shirt where she'd pulled it so far. His warm fingers brushed against her cold, gray skin, and Seteth was suddenly aware of just how close he was to her. There was no struggle from The Demon, the awkward moment silent between the two. She didn't dare turn her head to the side, ignoring the possible intimacy of their compromising position. He worked the shirt over her head, careful around her horns (were they always so sleek?) so that he didn't rip her shirt further. Once her head was free, he carefully pulled the shirt around the arrows before gently folding the clothing and setting it by the door. 

Despite the species stereotype, Byleth showed _no_ skin. What wasn't covered in armor was covered by a shirt or her large jacket. Once stripped from both of these, her bare gray back was laid out for him, the tight skin over her muscles scarred and gnarled from previous injuries. It shouldn't have startled him, seeing her skin the same ashy gray as her face, but so much of it caused his cheeks to redden against his wishes. " **How many arrows?** " Her gravely voice brought him back from his fluster. 

"Three. I'll be gentle." 

" **Why? Just yank them out.** " Seteth had a sinking suspicion all of these scars on her body had something to do with that mindset. His thumb absentmindedly traced over one of the more extensive scars, a thick, twisted raise of her skin that spiraled around her shoulder blade, almost pierced by her arrows. 

Her skin was cool to the touch, but the scar felt warm. " **His name was The Bull. His horn.** " How did she know which exact one he was touching? Her back was almost covered. He changed his trajectory, tracing a thin line down the center of her back, roughly parallel with her spine. 

The Demon shivered slightly. " **An obsidian blade. I was distracted in battle with The Disillusioned, and The Vulpine slipped behind me and managed a hit.** "

"How do you remember all of these?" He murmured, refocusing his attention back to the three arrows. 

" **Anyone capable of landing a scarring blow on me is worth remembering.** " Her fingers rose to brush against her lip idly. Seteth's earns burned hot once again: did that mean she would tell the tale of Seteth's spar for however long she lived? The Demon all but read his mind. " **I would tell of our battle, but someone healed me immediately after.** " 

"You didn't seem to mind." White magic began to swirl around his palm, preparing to extract the first arrow. "This… might spur a few complaints, though. I apologize." His fingers wrapped around the bolt, the weapon flaring with his magic as well. 

Byleth didn't stir. " **...** " He worked the arrow around until it slipped through its entry point with little to no resistance. Even though she didn't utter a word, Seteth could tell it hurt. She flinched, but she didn't cry out. 

"Are you okay?" The light from his hands seemed to slide into the wound, healing the skin back together so that its prior presence was undetectable. When his thumb finished tracing the circumference of the first arrow hole, it had sealed completely — a little bit of the tension she'd been holding in her shoulders relaxed. 

" **I am. Thank you.** " 

The words were sincere, even if she disliked them. "You are welcome, Byleth." The Demon relaxed posture stiffened, ears flicking back in shock. That was the first time he'd called her by name. Her chains and earrings rattled with the jerky movement. Seteth spoke again. "I have many things I should apologize about, but you had the grace to do so, so I must follow suit." 

His hand wrapped around another arrow, wincing on her behalf as he worked it out as gently as possible. " **You owe me nothing. It is not like we started on the right feet."** Seteth smiled at the botched reference but said nothing. " **All we can do is make it better as we go. You have no more reason to distrust me, and I have no more reason to dislike you anymore.** " 

Seteth pulled the second arrow out, the hand braced on her back immediately aware of the goosebumps that had formed under his touch. The magic surged through her once again, healing up the second arrow wound. "You are taking this remarkably well." 

" **Can't show weakness or the pack will eat you alive.** " Her shrug seemed like it pained her, but it was more important to her to get the gesture out. Seteth prepared himself for the last arrow, bracing his hand on her back once again while the other prepared to maneuver the final shaft. 

"Do you need me to take it out faster or slower? I do not want to make it worse." Byleth snorted. _Go slower. Your hands are warm_. 

" **Faster. Just get it over with.** " 

Steeling his resolve, Seteth nodded. _I do not want to hurt you._ "Very well. The first two healed without a scar, so if we are careful, you will heal just fine." Taking the small nod from Byleth as consent to continue, Seteth began to pull the arrow out. 

" ** _Agh_ ** !" She hissed, jerking forward in pain. The arrow ripped out, tearing at the muscle. A consistent stream of blood began to ooze from the wound. " **Sorry.** " 

"Do not apologize. I'm sorry-" He pressed his hand against the injury, magic sealing up the final bit of broken skin. Uninhibited by the arrows now, Byleth rolled her head from side to side and stretched her arms over her head. The Priest focused on healing rather than the sudden realization her front was topless too. This situation was inappropriate. 

When his hand moved and the blood smeared to the side for inspection, a small, jagged scar remained from the final arrow. Byleth's eyes flashed as the scar was committed to memory. "I guess it is my turn to apologize. It seems the extraction was not entirely seamless. You will have a scar." 

" **Don't apologize. It is one of many.** " She murmured, rolling her shoulders again. " **I hate to kick you out, but I am in desperate need of cleaning.** " 

"No, no, no need to worry. I will leave some clothes for you to change into while we have yours cleaned and mended. I will place them at the door." He stood and averted his gaze from her, focusing on _Goddess, anything else_. "Take all the time you need. You deserve it." 

The words startled her, freezing her mid-movement. " **Excuse me? What did you say?** " Her tone was flat, devoid of any emotion to assist Seteth with discerning how she felt. 

"You did well. You deserve some rest. It is not a bad thing." Anxiety gripped at his belly as he tried to navigate the slippery social ground they now had before them. The gates to communication were open, both participants willing to meet in the middle, but they both also floundered like newborn calves in the process. He found himself desperately wanting to try, but not knowing how to move forward. Byleth was struggling with emotions, but was he struggling with some to?

" **...** " Byleth stared down at her hands before giving him a non-committal grunt. Taking his leave, Seteth slipped out of the bathroom and placed some extra clothing from his closet outside the door. Something large enough to fit around her horns, and long enough to cover her arms. Mercedes was amazing with thread and needle, but even she would need a day or so to perform her garment miracles.

When Seteth left, Byleth finished undressing and drew a warm bath, letting the steam all but fill the room. The ash and blood seemed to fade away as she sunk lower into the water. “ **What do I deserve?** ” She whispered, hands trailing up her arm to touch a scar. The same light filled her eyes from earlier, the perfect recollection of battle wounds. " **Scarlet Raven. Talon Slash.** " As her touch continued up to her shoulder, she pushed against another one. " **Butcher of Guera. Bite wound in battle.** " 

Finally, her hand reached to brush against the newest scar, a jagged rip. Her eyes lit up with magic again. " **Seteth Assal. Arrow removal caused from protecting his daughter.** " She sunk a little lower into the water until her nose was almost submerged. Even though she’d saved Flayn, there was a part of her that enjoyed putting The Death Knight in his place. She was still a Demon, even if she had these emotions. " **I… deserve these. That is what I deserve.** " 

It would continuously serve as a reminder of the two green-haired humans whenever she was sent back home and away from the human domain. This one would stand out, though. Instead of being gored by horns or sliced by surprise swords, she’d remember a gentle healing touch and thick, green curls. _And the smell of chocolate_. 

Her shoulders relaxed as her body attempted to do the same. She'd done a good thing, and that little girl was proof of it.

“ **...I guess I deserve to relax too.** ” 

**Notes for the Chapter:**

> *the ship begins!* 
> 
> Another HUGE thank you to froggykind for Demon Byleth AU Art!
> 
> Thank you so much for reading <3 
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	9. Demonology

**Summary for the Chapter:**

> Seteth and Byleth discuss Demonology, and the Monastery's dark secret.

Byleth rested in the water for a bit longer, making sure she was clean before stepping out and toweling off. She’d had a good bit of time to think about things, but the water had lost its warm bite, practically forcing her out. The door cracked slightly as she pushed her hand through the crack, grappling for the clothes that Seteth had set out for her. It was unfortunate she’d be stuck in unfamiliar clothing, but it couldn’t be helped. The cloth was cloth, and coverage was coverage. If she felt too uncomfortable, she was sure it would take no time at all to don her armor and fall back asleep, just in case something attacked in the night. The moment one grew complacent was the moment one lost the battle. 

The garments smelled heavily of Seteth, likely coming from his closet. What might have repulsed her previously did not have the same effect; she’d grown accustomed to his scent and had it committed to memory. It was easy to lose the Priest amid Garreg Mach Monastery life, so utilizing their link or his scent helped suss him out in the middle of his stuffy meetings or to find him for mealtime. It didn’t matter. This change in regalia was only temporary. It was hard not to think of the green-haired man as she slipped into the large shirt, though. Careful not to pull too hard and rip it with her horns, she let it relax around her. It covered everything that needed to be covered, sleeves reaching down to her knuckles with its size. 

Was he really bigger than her? Perhaps her larger-than-life persona and armor made her feel larger. It was not often they were… close. Outside of their fighting pins (they both seemed to be fond of it), there had been a healthy distance between the two. The majority of the times he’d healed her had been for back wounds, or immediately after a spar. This was her first glance at their size difference. She didn't like it. _Fine. He may be bigger, but my true form could crush him with my tail - No, a toe._

Not that she ever would. _Whatever._ She moved to slip on the pants, struggling despite their loose nature. Her tail had nowhere to go. If this tailor could perform miracles, they’d be able to sew up the pants easily enough after she mangled them. Using a claw, Byleth sliced down for her tail to push through the pants so she could wear them. One, two, three test flicks - Perfect. Her eyes slid down to the armor on the floor. She didn’t need that, did she? Not right now, at least. Excited at the prospect of an evening without the worry the cold, biting metal digging into her skin while she slept, Byleth made her way out of the bathroom. 

\---

Seteth’s back leaned against the headboard of his bed, tired eyes reading over a few loose papers in his hand. While Byleth finished cleaning up, he elected to peruse through some of the matters that had gotten neglected today. The longer Rhea sat in her sickness, the more that piled up on Seteth. It was getting harder and harder to keep up, and at this rate… He pinched the bridge of his nose, pushing his glasses up and out of the way. _Rhea, please wake up. I am beginning to struggle._

The door opened, releasing the last remnants of steam from Byleth’s bath as the Demon herself stepped into the bedroom proper. She’d put on the clothes he set out for her, with a few modifications for her tail.

The man couldn’t help but blink, taking in the new look of the Demon. She seemed so different without her armor and jacket. Here, without everything that made her feel comfortable, Seteth couldn’t shake the feeling he was seeing Byleth in a new light. 

It made him uncomfortable. 

“ **You’re staring.** ” Her gruff voice startled him, causing him to fumble with the papers in his hands a bit too quickly. They rattled under his touch. 

“Apologies. It is different to see you without armor.” It wasn’t a total lie. He placed the papers on the nightstand, as well as his glasses. 

“ **After what I did down in that underground chamber, nothing is going to bother the Monastery for a while. I figured I could actually relax for once.** ” It… also wasn’t a total lie. “ **Besides. I am here with the strongest human in the Monastery. When we are not busy kicking each other’s asses, I assume we would make a formidable joined force on the battlefield.** ” 

Seteth chuckled. “One can only hope the ass-kicking is behind us.” Byleth shrugged, striding past his bed towards her pillow nest. It had been straightened, piled up, and pillows fluffed. 

She didn’t react, merely flopping down and curling up. After a few seconds, her head appeared over the bed’s edge, chin resting on the mattress while they continued to speak. “ **Indeed. It would be a shame to trounce you in front of your students.** ” Seteth’s eyebrow raised incredulously, recalling the spar he’d won. “ **Relax. It was a jest.”**  
  
“As were your fighting skills.” He smirked, catching the heated glare from the edge of the bed.

“ **The Monastery is going to be very upset when they find out a pillow smothered you in your sleep.** ” 

Their banter was light, despite the death threats and prodding into combat critique. “At least lie to them for me. Tell them I died fighting a dragon.”  
  
For some reason, the Demon snorted with amusement. “ **I know a few. I could make that happen.** ” 

He held up his hands in front of him. “I think I will pass. What I would like to know more about is this Demonology discussion we’ve kept tabling.” The curtains shifted as Byleth’s tail flicked, interest perking her ears slightly. “To hear you tell it, there is quite a bit that we are not aware of. I have laid eyes on every book that is in the library, as well as all that are added. If information were missing, I would know.” 

“ **It’s not that the information isn’t written. It’s just not** ** _there_** **. Humans won, so why would they include any of their soiled histories when they could rewrite it?** ” Seteth did not like the implications of that statement. His hand reached for his glasses and a quill so he could begin to write notes. “ **You won’t like what I have to say.”** **  
****  
**“Try me.”

 _I wouldn’t mind._ Her intrusive thoughts shouldered past, beating into ribs as her heart thudded. She bit it back. “ **Very well. It is lengthy.** ” 

“I have a bottle of ink.” 

Fine, if he wanted the truth? Might as well tell him. Demons all but passed down the history for the sole purpose of keeping the anger alive for the weak race, and while her father didn’t present it in such an aggressive manner, it was almost a coming of age to understand just _why_ they were stuck where they were. Why life separated from the human plane was necessary. Why it was _forced_. 

Byleth shifted to get comfortable, preparing for a long conversation. “ **When the Demon Sothis created our race-** ” 

The quill snapped, breaking completely in two within Seteth’s hand. _This is going to take longer than I thought._ Seteth had hardly made it past the first sentence before cracking. “ **Is there a problem**?” 

Depositing the broken pieces on the nightstand, he moved to grab another, absentmindedly running a hand through his hair. “Forgive me, it was… almost as though I heard you say that Sothis was a Demon.” 

“ **I did. How do you think humans got magic? You were just born with it? It was a gift from Sothis, the Demon.** ” 

_Is the goddess truly a Demon?_ What did that make the Church? What did that make _Seteth_? “I… will do my best to refrain from comments until your explanations are through. Just please understand, if there are more revelations such as this, that it will take a few moments for me to process them fully.” _A few moments, a few years, a few decades_. The Demon before him could stop time, and it still wouldn’t be enough. Puzzle pieces were missing. 

“ **Thank you. Otherwise, we’d be here all night breaking quills.** ” She cleared her throat and continued. “ **Humans and Demons got along, sharing existence. Sothis bestowed upon humanity the gift of magic. Those who were capable of learning manifested the abilities, and soon it became passed through bloodlines. Under the watchful eyes of Sothis, she and her four advisors - I believe you call them Saints? - helped the cohabitation of our two races.** **When Sothis saw that the world our two races had made was good, she fell into a deep slumber in the center of the world. It is said that is where she remains, completely unaware of the chaos above. In her stead, she left her daughter Seiros in charge.** ” 

A cold chill began to creep up Seteth’s back as everything he’d studied, everything he’d worked for, was being challenged. “Byleth.” 

She was still not used to being called her name. “ **Yes?** ” 

“If I had commanded you not to lie at the beginning of this, would you be in pain right now?” Seteth hated using the mechanic when conversing with her, or when reasoning with her, but he was not above it if it meant getting honest answers. 

“ **I am not here to play mind games,** **_Priest_** **. If you wish to command me, just do it.** ” Byleth spat, eyes narrowing. **“I would feel no pain, save for the sting of your continual distrust.** ” She’d saved Flayn, eliminated enemies beneath the Monastery itself, and worked rather peacefully with Seteth over the past month. “ **If I wanted to do something heinous, I would have already done it by now. When I am speaking with** **_Seteth_ ** **again, I will continue.** ” 

Oh, how he hated the way she spat that word. Priest, as if it were an insult rather than his position. It was not unlike how he spat the word Demon at times, though. Her words stung, not because of their bite, more so because she was right. Life had been as good as it had because of his caution, his distrust. Everything to protect himself and Flayn. How easy it was to forget that Byleth had done the same. Others could argue she did it because of her love of battle, but others had not seen Flayn sleeping soundly against her. Others had not felt the emotions Byleth exuded through the underground fight. He had claimed he’d never be able to raise a hand against her, and yet here he was, using the same hand to push her away. “You are absolutely correct, and I am sorry, Byleth. I did not mean to offend and am… working on it.”

The Ashen Demon wrinkled her nose, removing her chin from the bed so that she could back up to sit against the wall. Her tail moved in front of her, resting in her lap. “ **Apology accepted, Seteth.** ” His shoulders relaxed at the sound of his name on her lips, a more comforting sound than the scathing title he’d gotten earlier. “ **The name Cichol had been familiar, but I could not figure out why. He was one of the advisors to Seiros, alongside Cethleann, Indech, and Macuil. Together they assisted Seiros alongside the human kings. This was, mind you, about 5,000 years ago?** **How far does your history go back?** ” 

“A-about 4,550 years, if I remember correctly.” 

**“Oh, it’s correct, alright. It was about that time that humanity began to realize that if anything happened between the two races, the humans had no chance of overthrowing them or fighting back. So, they mobilized and attacked us.** ” Her eyes searched his face, looking for any hints of emotion, but he was almost as good as her when it came to stifling them.

The only change was his furrowed brow as he continued to write. “But why would they attack if their inevitable loss in war is what started it in the first place?” 

“ **They didn’t attack like that. They gathered assistance from Demons that wished to stay on this plane but also pledged allegiance to humans, rather than their own race. Between humanity’s magic and the Demon traitors, they were able to banish all other Demon blood to a separate existence.”**

The writing stopped as it suddenly dawned on Seteth. “A separate plane.” 

A small frown tugged at the edges of Byleth’s lips as she continued. “ **Indeed. Your ‘Saints’ were banished along with the rest of the Demons, and Seiros all but disappeared. She has yet to be reincarnated. We can only assume the worst. That being said, Demons had to build anew while humans reaped the benefit of Sothis’s gift without us. We retained our power because we** ** _are_** **power, but we were forced to start over.** ” 

“What was it you had said?” Seteth scratched at his stubble in thought. “History is written by the winners?” 

Byleth nodded. “ **Indeed. With the majority of Demons gone, humanity was free to say whatever they’d like about what had happened. There needed to be** **_some_ ** **explanation of magic, so Sothis became a divine being in your texts, and her advisors were ‘saints.’ To explain away the phenomenon of the progression of diluted Demon blood, given those that remained-** ” The Demon’s eyes locked onto him, hesitating. **“-they called it ‘Blood of the Goddess.’** ” 

\---

 _Snap._ The edges of the broken quill bit into the soft flesh of his hand, drawing blood from the force. _Blood of the Goddess is Demon’s blood. Blood of the Goddess is Demon’s blood._ The truth roared in his ears, drowning out all other sounds. Who had a Demonic ancestry between Seteth and his late wife? Goddess, this was not how he wanted to stumble upon thoughts of his deceased partner. He could hear Byleth saying something to him. She was moving, that much he could see, but the sound never reached his ears. 

“ **Seteth.** ” 

Seteth or his late wife had an ancestor that had remained in their world, betraying their own kind. What had been seen as a gift for so many years was a tainted- No. Not that word. _Never_ that word. Whether it was he or her that shared the ancestor, that did not change who they were. 

Nor did it Flayn. 

But it changed so many other things. Everything they knew was wrong.

“ **Seteth!** ” 

Rough hands gripped his own, the eerie, red glow of Byleth’s magic enveloping them. The dark magic forced the broken skin back together, the last trickles of blood pooling into her palm. The slight discomfort shook Seteth from his thoughts.

Byleth was standing by the bed, healing him. “Forgive me, I-”  
  
Byleth shook her head. “ **Worry not. I know. I figured it would be like this, the moment I found out why they were looking for Flayn in the first place.** ” The magic faded, leaving Seteth with healed hands. The execution was flawed, and he could tell that it had taken far more effort than it should have, but Byleth had mentioned that healing was not her most substantial ability. The gesture had not gone unnoticed. 

“My wife died right after Flayn was born nine years ago, so I do not know if it was her or I that shared the ancestor. Is there a way to tell despite her not being here? Out of morbid curiosity.” Neither of them could control what their ancestors had done, but the closure of knowing was something Seteth wanted.  
  
 **"Yes, there is a way. Do you truly wish to know?** ”

 _Yes._ Not for self-flagellation or to lose even more sleep over, the precious resource all but mocking him every night. If his eyes were going to be opened to the whole truth, he might as well know everything about what this meant for Flayn. He nodded. 

One of Byleth’s hands rose to her face, a few lines of blood from his cut still fresh on her gray skin. Before Seteth realized what she was about to do, Byleth's tongue slid up her palm, lapping up some of the bright-red liquid. Something stirred within him. Something he quickly buried once again. 

After appraising the taste, Byleth chuckled. “ **It’s not you, but do not fret. It means next to nothing. It is diluted over thousands of years. She will excel with magic, and that is all it means.** ” The non-bloodied hand still remained on his, a fact she was only now aware of. She slowly pulled away, clearing her throat. “ **So, don’t worry, or anything like that.** ” 

His hands were cold again. “Thank you. I did not mean to derail us.” 

“ **Hey, do not worry about it.** ” She grumbled, returning to her nest so she could resume leaning against the wall amongst the pillows. “ **To a human, I’m sure it sounds worse than it is.** ” 

\---

She wasn’t surprised at his reaction, finding out his daughter had demonic heritage. Byleth had no reason to lie to him, even if he had been afraid of it previously. To see him react so powerfully meant that he believed her. So why did she not feel relief? Was it because Flayn, even if it was a single drop over thousands of years, was like _her_? She did her best not to be offended and let him process. “It is just a lot to process. This changes nothing about Flayn in my mind, though I do have a lot of questions for Rhea when she is awake again. I suppose this is why you and Flayn clicked so well then?” 

“ **Entirely possible, though I think that had more to do with her personality than anything else. I do not fawn over full-blooded Demons, so why would a drop of Demon blood make a difference?** ” Something about her answer seemed to satisfy Seteth, who nodded and shakily grabbed another quill. 

“If you are willing, I am ready to continue. No doubt there is more, yes? We left off 4,550 years ago?” 

At least he was paying attention. He leaned her head back until her horns clacked against the wall, caps scraping slightly. “ **Yes, though there is not much timeline left. After Demons were banished, they were forced to start anew. Kings came and went, many scrambling for power - once they got it, it was an even harder fumble to keep it. It wasn’t until King Jeralt, The Blade Breaker rose to power that things started to really smooth out. That was… 3500 years ago. Since then, he’s been king. His first child was born 2,000 years ago, but shortly after his wife was killed and reincarnated into something else. Someone new.** ” 

The quill scribbled quickly across the paper as Seteth took notes. “So when Demons die, they are reborn?”  
  
Byleth nodded. “ **Yes. You retain the memories you had from your previous lives, but you are a different person.** ” Her grip tightened on her arm. **“And the people you loved or knew, you do not have the same feelings anymore. Such is the way of life. If we were the same every time we came back, nothing would be different.** ” 

“I can see how it would add variety, but how tragic. To lose a family member, only to have them come back with no feelings for you. If I were to die and come back to feel nothing for Flayn, what would be the point of living?” The thought was almost incomprehensible. 

“ **How very human of you.** ” Although her voice was sad, her slight smile was gentle. “ **But yes, it would happen such as that. It is because of this that King Jeralt took no more wives, and set to raise his only daughter in hopes of her taking over. Previous kings were very anti-human, ready for aggression, and to spit on your corpses. Any opportunity at a summon was a Demon’s opportunity to slaughter. King Jeralt, however, emphasizes Demon-kind. Do what you want, but protect the pack mentality. It is because of this that I was raised with a tolerance for humans. I would not have slaughtered Claude when I pointed at him. I had already promised that no harm would come to him. I** **_do_** **have a reputation to uphold, however. Once I was finished, I would have just run off to enjoy life unbound.** ” 

It hadn’t been that long ago that their first meeting on that bloody, monster battlefield resulted in Claude’s life being threatened when time was stopped. His shoulders relaxed, knowing it had been a facade. “While I am glad that is the case, if we could avoid any more bluffs in the futur- wait. You said you were raised that way. Does that mean that The Blade Breaker raised you?” Byleth nodded. “So you are… his daughter?” She nodded once more. “ _Goddess…_ ”

Byleth’s chuckle was hearty. “ **I believe that hit the main points of history. Did you have any questions?** ” 

The Priest leaned his head back against the end of his bed, mentally exhausted. “Yes, like did Rhea know _any_ of this?” Seteth ran a hand through his hair, slowly. “I’d hate to know that she knew all of this, and humanity was kept in the dark.” 

“ **Would you blame her if she did know? Some secret Archbishop’s handed down from leader to leader? What would it change? Would humanity truly be ready for the truth?** ” Byleth did have a point. Seteth chewed on the tip of the quill, a nasty habit he’d yet to kick. 

“You have a point. _Goddess_ , I just wish I could ask her.” 

“ **I cannot help in that regard, but perhaps I can take a look at her. See if there is anything I recognize or a way to wake her. That** **_is_** **, after all, why you have bound me.** ” 

Seteth paused mid-chew, thinking. She was correct. This _was_ the entire reason she was here. She could help them fix whatever is wrong with Rhea, and then she would go back to her own plane. Everything would go back to normal, and life would continue. So why did that plan sit so ill with Seteth? “Yes, it is… I suppose it would not hurt for a moment, but only a quick evaluation. We will not be doing anything tonight while you have yet to rest.” 

Byleth’s ears flipped back in annoyance. **“Why would I need to rest? I slept all day.** ” 

“Yes, but you healed me, and I know that took more magic out of you than you wish to convey.” His hand lifted between them as if to stop her protests. “I do not doubt your power, but only wish to glean information first.” 

“ **Very well. Lead the way.** ” 

\---

Many of their midnight walks had been for aggressive reasons. Looking for Flayn or The Death Knight, walking to the Training Grounds to beat the tar out of one another for respect, or to get Byleth places without prying eyes. Moving around this late at night meant no students would get in the way. There were no distractions or issues. Thankfully, Rhea’s quarters were not far either way. It was rather chilly outside. 

Seteth opened the heavy oak door and let Byleth slip inside before he closed it and latched it shut. _Goddess, I hope this yields results._ His prayer felt flat, though. Knowing Sothis was asleep at the core, and was actually a Demon, meant that there was little chance she was pulling any strings. Little chance of assistance. Little chance of _hope_. Byleth had once told him that the Goddess could not grant him what he needed, electing to do it herself. Instead of putting faith in others, she worked towards her own results. As the Demon began walking up the steps that led to Rhea’s chambers, Seteth could only hope that she would prove him wrong once again, even _if that means Byleth leaves._

“Here we are.” Seteth unlocked Rhea’s doors, pushing them open. They groaned in protest, heavy and reinforced in case the Monastery was attacked. Byleth’s snort did not go unnoticed as Seteth gestured for her to enter. 

“ **It smells like death in here.** ” 

The Priest paled. “Byleth, please do not say such things.” 

The Demon rolled her eyes as she walked forward, into the large, spacious room. “ **Fine, but it does.** ” She beelined to the bed where Rhea lay, sick and pale. 

“Her condition has been worsening. As time progresses, she gets paler. For a being that has lived so long, I cannot fathom that this is when she passes-” 

“ **Repeat that last bit. What do you mean, a being that has lived so long?** ” The Demon’s eyes seemed to glow in the low light, drinking in every visual detail of Rhea she could. 

While Seteth did not think it was necessarily pertinent, he indulged her. “Rhea has been around since the beginning of the Church. The Goddess, er, Sothis, blessed her with the secret to a long life. The Archbishop that comes after her will be given the same gift on Rhea’s deathbed, as the texts foretold.” 

Byleth’s cackle of amusement echoed in the large chamber. “ **Yes? And how has that worked for you? She cannot do that for anyone right now, can she?** ” 

_Byleth, do not push your luck._ “Byleth, you would do well not to disrespect our Archbishop in such a manner. I know that this is foreign to you, but understand that certain respect is to be adhered to-”

 **“She’s a Demon, like me.** ” 

If Seteth had a quill in hand, it would have snapped. _Byleth, don’t you dare drop another earth-shattering realization on me._ “Forgive me. Did you say _Rhea_ the _Archbishop_ is a _Demon_? If the Archbishop were a Demon, I would have known.” _She would have told me. She has told me she trusts no one else as much as I, as her advisor!_ Rhea was practically family.

Sensing the turmoil in his heart, Byleth’s jaw clenched slightly. She did not answer immediately, instead hopping onto the bed to investigate Rhea more closely. Everything Seteth’s body screamed at him to stop her, but he remained silent. This was her job, so he left her to it. Anything for her to see she was incorrect.

\---

There was no mistaking it. All of this was for show, so Seteth would have a little more time to process Byleth’s words. The elongated fingernails, pale skin… Byleth placed a hand on her head, running her claws through the woman’s hair. Nubs on her head. Horns were growing back in. If what Seteth said was correct, and Rhea had been asleep for quite some time, this Demon held _immense_ power to keep a human glamor up for so long. The smell of death clung to her skin, though she was very much alive. _Someone wants her dead. Someone rather powerful wants her dead. This is the work of The Plague._

“ **Okay. How much unpleasant news do you want at a time?** ” Byleth refused to dance around the topics for too long. 

Thankfully, Seteth was not one for beating around the bush either. “Just… everything. Please.” 

“ **Very well. Rhea is an incredibly powerful Demon, though I am not sure which one. I have not met this one before. She is unbound and has been for a long time. She is under a curse of death, thanks to a Demon named The Plague. Her handiwork only works on other Demons, so she's useful as an assassin of sorts.** ” Byleth wrinkled her nose in disgust. **“Nasty little bitch, never did like her. However, that means that someone has The Plague contracted as well. I would bet my tail The Plague is contracted by the same person who summoned The Death Knight.** ” The Demon paused to study Seteth’s reaction. His arms were crossed, but his fingers dug into them. 

The man shook slightly but held his ground as he spoke, voice wavering much like his body threatened to. “Is… Is there any way you can prove that Rhea is a Demon? Right now? It is not that I don’t believe you; it is just that it seems entirely unbelievable. I am Rhea’s most trusted advisor. What is your basis on this revelation?” 

_I don’t want to do this._ “ **I can show you. Her skin is turning white, not from sickness but the human glamor failing. She must have an immense amount of magic stored to keep this going for so long. Her horns will be next, though I am surprised you could look past her claws…** ” 

“I assumed that they had not attended to her nails recently, given her sickness. A glamor, you say?” 

Byleth’s reluctant crawl off the bed took longer than she wished, akin to a pouting dog unwilling to return to its master after a day of play. Magic surged around Byleth as her skin color began to fade, growing in _life_. The sets of horns that adorned her head began to disappear, as well as her tail. Her earrings jingled as the ear changed shape, growing into the ear shell humans were known for, rather than goat-esque, long ones. Fingernails shortened from claws to average hands. By the time the magic fizzled away, there was a completely human Byleth looking at Seteth. 

Just like the mirror. 

Seteth looked as though he would be sick. 

To be fair, Byleth felt like she was going to be sick. “ **This is a glamor. I can keep this up so long as I am awake and capable of casting magic. Maintaining it is not difficult, but would be during my sleep. For Rhea to have lasted this long is incredibly impressive.** ” 

For what it was worth, Seteth seemed to be taking this in stride. It was a difficult pill to swallow when one’s religion crumbled to the ground, but he’d yet to go mad just yet. “I… see. In that case, you may revert back to your normal form. I have seen enough.” 

“ **Would you prefer me to perform a glamor so that I am easier to look at for you and the stud-** ” 

“No.” He blurted out, startling even himself. The answer came too fast for Seteth’s liking, cursing his reaction. The words had slipped out like water, smooth and necessary. “I mean, no. I do not want you to stifle wha- _who_ \- you are. You are not Byleth, The Ashen Demon, without everything that makes you who you are.” His gaze shifted over to the sleeping Rhea. “I do, however, wish to know more about her. What makes her who she truly is. I’m afraid I will leave this room with more questions than I entered it with.” 

“ **I am sorry.** ” 

“There is nothing to apologize for. You are the only lead we have had so far. Is there any further info you could glean from her?”  
  
The glamor began to fade, Demonic features returning to Byleth’s body. Once fully manifested, her tail thrashed to stretch out. “ **Possibly. I can return at another time.** ” 

Seteth nodded. “Of course. I will give you a key. We need to know as much as we can about her as possible, and if you do not mind, I would like a full report on The Plague and The Death Knight.” Byleth glanced over at him, smirking. “What? Did I say something funny?”  
  
“ **No. I just find it amusing. I will write your silly reports, Seteth.** ” She purred, looking over her shoulder at Rhea one last time. Something about this didn’t feel right, but without trying to expend magic to investigate the curse, there was not much she could do tonight. This was a problem for future Byleth. Present Byleth wanted to sleep, so she wrenched open the loud, groaning door. “ **A** **fter you.** ” 

\---

As they began the short walk back to Seteth’s chamber, the Priest let out a long sigh into the night air. “You need to give that Demonology seminar. The students are all but begging for it, and it would certainly help your image across the grounds. But I wonder how much you should reveal. I would be unsurprised if the majority of the Monastery attended, but for such robust information to get out in such an uncontrolled manner. Giving these secrets to teenagers seemed like a terrible idea. 

Byleth took a moment to think, claw tapping her chin thoughtfully. “ **You are correct to be cautious. We do not wish to cause chaos. I suggest nothing of the Saints or Sothis.** ” 

“That seems wise. History and a general question and answer session would suffice. Are you willing to perform such a task?” He could always command her, but that was not the way they were operating anymore. 

“ **I do not mind. Allow me to sleep in. Also, the month is rapidly ending. I did not consume any of the victims, so I will need some sort of offering within the next day or so. I would be willing to perform this lecture in exchange for it.** ” Her stomach rumbled at the thought of such a meal, delicious marrow cracking between her teeth, soft meat to rip into...

The idea seemed to sit well with Seteth too. “Very well. I can make that happen after the lecture. It is a deal.” The Priest stopped walking so he could stick his hand out for her to shake. Her bright eyes flicked between his face and his hand for a few moments before she gripped it in a tight hold. They shook once, concise and strong before their grips released.

“ **The pact is sealed.** ” 

“Do you have to say it like that?”

“ **No, I just like the way it makes you squirm.** ” 

“Always a delight.”

\---

The stage was set. Due to the overwhelming torrent of signups for Byleth’s Demonology lecture Seteth had elected to cancel all other classes. It was not like anyone would show up anyway. To ask and have questions answered by a real, willing Demon herself? The opportunity was too good to pass up. The students understood this if the paper that was completely filled with names - outside margins, between the lines, all over the surface - was any indication. 

No lecture hall was big enough for the feat, and it felt like blasphemy to suggest the Cathedral - plus, could Byleth step inside there? - so they elected to bring chairs in an arc around Byleth’s favorite gazebo perch. From there, she could stand on top and address the Monastery in attendance, or lounge at her leisure as she spoke. There was room for pacing if she ended up walking as she spoke. Everything was ready. Students began to file around, taking their seats while whispering to themselves. Claude waved down Seteth, who only acknowledged the boy with a slight dip of his head. When it seemed everyone was in attendance, all they could do was wait for the teacher to arrive. 

Seteth stepped back to sit with the other professors, Manuela and Hanneman, already bickering under their breath. “Please, settle down. Byleth will be here at any minute, and we will begin.” Seteth always managed to diffuse their situations relatively quickly, be it by pure intimidation or actual conversational skills. Half the time, Seteth never stopped to figure out which one it was. 

“Yes, yes. I will settle as soon as this infuriating woman scoots her chair a bit to the side! I do not want to feel her leg bouncing through the entire lecture!” Hanneman growled, shooting a sharp glare at the woman beside him. Manuela, not to be outdone, shifted closer to him, if only to annoy. Seteth pinched the bridge of his nose in annoyance. _Seiros give me strength._

It was not Seiros who answered his thoughts, but Byleth. In a rush of wind, something whizzed past Seteth, ruffling his robes and hair. The students murmured, startled, as a zipping figure circled overhead, wings slowing their beating for them to descend. Byleth’s feet touched the top of the gazebo, wings folding behind her back neatly. Her tail swished idly as her eyes scanned the crowd, lingering on Seteth for only a hairsbreadth longer than the others. Manuela and Hanneman clutched one another, terrified. “ **Welcome to Demonology. I am your professor, The Ashen Demon.** "

**Notes for the Chapter:**

> THERE IS A SETLETH FANZINE CURRENTLY IN THEIR INTEREST CHECK - GO CHECK THEM OUT [ Setleth Fanzine ](https://twitter.com/setlethzine/status/1221195052959051777)
> 
> Thank you for reading <3 We've got our worldbuilding exposition out of the way: TIME TO SHIP BEACHES
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	10. Waltz

**Summary for the Chapter:**

> The final stipulation for Month 1 is met. Byleth sleeps. 
> 
> Seteth extends a hand, with a little help from some wine.

Byleth’s lecture was, without a doubt, the most successful one Seteth had the privilege of watching. Student interaction was at an all-time high, and the subject matter kept them all engrossed as the Demon answered various questions. The change in perspective made many of the students anxious, a few of them turning to find Seteth’s face within the crowd. He gave them head nods and glances to back up Byleth’s claims, occasionally asking a question himself to keep the discussion moving. Byleth commanded total attention, the sheer aura of power wafting off of her. She had everyone in the audience captivated, even himself. From the simplest of questions, such as what happened when a Demon was Summoned (The answer was, of course, an immediate tear away from whatever the Demon was doing at the time) to the more involved questions regarding the timeline, Byleth handled them excellently.

All in all, it was a successful afternoon of information. 

As the lecture concluded, students began to disperse for food. Seteth was surprised when many of them went to speak with Byleth now that the seminar itself was over. She seemed equally surprised, her eyes searching for his over their heads. How amusing it was to see her flounder around the pack of students, her confident eyes flicking back and forth between the many voices. The attention was a bit overwhelming for her, he assumed. When her ears lilted backward to press against the sides of her head, he stepped in. “Thank you for your enthusiasm, students. Let The Ashen Demon retire for food, and I am sure she will be up for more questions after.” 

Byleth’s shoulders relaxed as the students nodded and waved, taking their leave so that the two adults were left to their own devices. “ **That was easy until they all wanted to talk afterward. Having suffered their staring for weeks, it felt like such a shift of mood.** ” 

“You were quite popular, but only time will tell of their intent. Either way, you did well. My only note... Was such an entrance necessary?”  
  
“ **Establish dominance early; the rest of the pieces fall into place.** ” Her smirk was contagious, for Seteth found himself smirking as he shook his head. They walked, not in the direction of the dining hall as she’d expected, but back towards Seteth’s chambers. “ **Are we… not getting food?** ” 

The door opened with a click, allowing Byleth to step inside first before Seteth followed suit. “No, you certainly are, I just took the liberty of having everything brought up here so that you could decompress. If I was wrong in my assumpti-” 

“ **It is perfect. Thank you. I’ve said too many words today. I am content with silence.** ” 

That was something he certainly didn’t hear every day, given how challenging the Demon could be. Or, in rare form, how annoying. There was a large spread waiting for her, various meats with different glazes in different ways of preparedness, namely raw to medium rare for her choosing. Upon first inhale, her stomach growled ravenously, the slits of her eyes dilating.

When Seteth returned an hour or so later, Byleth was asleep on her nest, every scrap and drop of food clean. She’d left nothing but fingerprints. The sigil on her chest shone bright with her contentment, the final stipulation filled for the month. His chest was shining in response, a phenomenon he’d never quite get used to.

\---

Byleth’s sleep had been restful in the sense that she’d slept for an entire day. Exhausted from transforming one night, teaching two days later, and then having the most significant meal she’d had since coming to the human realm? Were she one of the cats that rubbed against her legs as she walked through the Monastery paths, she’d be purring. 

There was a different feel to the air as she walked. Students did not shy away, electing to wave or acknowledge her presence with subtle tilts of their heads. Flayn was all but ecstatic to see her walking about again, leading the Demon to the grand hall where Seteth was assisting with decorations. Decorations for what? 

At some point, Flayn had stopped talking, bright eyes blinking up at Byleth for some sort of answer. 

Also, at some point, Flayn had grabbed her hand to pull Byleth through the crowd that had gathered to watch the set-up. “ **Forgive me. I did not hear what you said.** ” 

Byleth doubted the young girl before her was capable of holding grudges. “That is okay! I _said_ , are you excited for the Ball?” 

The Demon cocked her head to the side, narrowing her eyes. “ **Ball?** ” Flayn’s hand slipped out of her clawed grasp, running to the approaching Seteth. The gaudy decor, the tables all but pushed to the side to make room in the center of the room… It made sense now. She’d heard of such human festivities but had never been on plane to attend one. “ **Ah, I-** ” 

“Flayn, it is good to see you.” The green-haired burst of energy all but slammed into her father, wrapping her arms around him in a quick hug. 

“I brought Byleth to see the Ball preparations.” 

His eyes flicked up to see her, amused to see her out of her nest. “I see that. She had quite the past few days. I do not blame her for sleeping in. Did Flayn explain our tradition?” Seteth turned to gesture at the room around them. “We set it up so that students may dance and mingle for an evening of fun and relaxation.” While Byleth could see the appeal in a night of relaxation, for _everyone_ to relax seemed dangerous.

“ **And what do the professors and Knights do?** ” The Priest could already tell what direction her inquiries would take. 

He pushed the glasses up his nose and patted Flayn’s head. “Well, professors chaperone-” 

“Awwwwwww no!” Flayn whined. 

“- and the Knights both chaperone and patrol, as normal.” 

Seteth had hoped the answer would satisfy Byleth, but she began to pace towards the center of the building. “ **So many openings, it’s hardly easy to guard, and you’re gathering** ** _everyone_** **in one place with no armor or weapons? Patrols are nice, but I do not see the practicality.** ” 

“There does not always need to be practicality, Byleth. Sometimes it is about having fun. A break, if you will. If you are so concerned for the safety of our students and faculty, would you be willing to stand guard?” If he were entirely honest, he couldn’t imagine Byleth attempting to navigate the ballroom anyways. Her steps were too large, and she was too free with her tail. She wouldn’t have enjoyed the event, but part of him still hoped she would attend in some way.

The thought made the Demon think for a moment. After a few moments of gear-turning, Byleth shrugged. **“Sure. Flayn will be there, and I can’t let you die because then I’m stuck going back. Might as well.** ” 

She fought so hard to seem so careless with her intentions, but the Priest knew better. He could feel the affection for Flayn through their bond. After such a change of heart from the student’s post-seminar, he couldn’t help but wonder if she felt protective over them too. Perhaps it was a stretch, but it wasn’t entirely unlikely either.

Seteth hid his smirk by turning around and fussing with a streamer. “Excellent.” 

\---

The Ashen Demon stared off into the horizon, eyes trailing away into distances unknown. Fodlan was vast and unexplored to her, every glimpse of anything beyond the Monastery walls a delight. It was there on the wall outside of the ballroom that she sat transfixed in thought, nothing but the moonlight and stars to keep her company. Her sensitive ears could hear the festivities in the building behind her, the low murmur of conversation and dance teasing her with its unfamiliarity. _This_ was familiar, though. The cold night air and darkness. Here she could be helpful and useful, and it was here she would be allowed to process the week’s findings. 

Curing Rhea was going to be difficult. The curse required death: either the death of its caster or enough death that the curse was satisfied. If she had to guess, given its demonic origins, it would probably take the lives of everyone within a mile radius. Since that could not happen, The Ashen Demon would need to track down The Plague, somehow. Perhaps if…

“Ah, hello, Byleth.” 

Seteth’s voice broke her concentration, his smooth interruption jostling her thoughts. Not that it was _unwelcome_ , no. “ **Priest. Enjoying your human ball?** ” 

“Indeed, but please, you are free to call me Seteth. Flayn has kicked me out so she can enjoy a few dances without my prying eyes.” He took a seat next to her, legs dangling over the edge with hers. When he spoke, Byleth could detect the slightest fruity scent, likely the wine they were pouring inside. 

“ **She is young, let her have fun.** **None of the students in there mean her ill will.** ” 

The Priest nodded, albeit reluctantly. “You are correct. That does not mean I’m not going to worry continuously. She is nine and just wishes to have a fun evening without her father, and that is entirely alright.” Maybe if he said it more times, he'd actually believe it.

Seteth’s lack of contentment with the situation made her chuckle, a low rumble in the back of her throat. “ **These affairs are supposed to be fun, yes? You do not seem to be having much of it.** ”

“I’m having enough of it. Manuela stole me for a dance, and after that, I have been chaperoning.”  
  
“ **Does that entail chasing everyone away from your daughter?** ” 

The Priest didn’t skip a beat. “Absolutely.”

Byleth rolled her eyes. “ **Sure, take away all of her fun. You humans do not live long, why not let her experience these things before they are ruined by age? Sweaty-palmed teenagers filled with nothing but self-resentment and hormones scrambling to impress others for an evening.** ” Youth allowed them to experience things without jaded opinions, and Byleth’s age all but jaded _everything_. 

“It sounds like you’ve been to one of these before. Do you have similar functions back on your plane?” His gaze was transfixed on the moon before them, large and bright against the dark sky. Byleth did not blame him. It was rather captivating tonight. 

“ **We have something similar, but they are typically a messier affair. If it doesn’t end with a bit of bloodshed, it wasn’t a good evening.** ” 

The thought rattled Seteth, ever so slightly. “I am glad for cultural differences.” His chuckle was infectious, spreading to her rather quickly. “So, you do not dance, then.” 

The draconic tail that dangled alongside her legs flicked slightly. “ **I did not say that, just that the equivalent affairs for my kind are unlike this.** ” 

“Well then.” He rose to his feet, brushing off the back of his pants from sitting, then moving to extend his hand. “If I am to suffer through the necessity of this event, so must you.” 

Byleth’s eyes glanced between his hand and face, confusion etched across her features. “ **What is this?** ” 

“This is me inviting you to dance.” 

Now it was Byleth’s turn to embarrass. 

The signs were small, but Seteth had learned to read them. Her tail went rigid, ears pushing back slightly as the jingle of her earrings gave the movement away in the darkness. He may not have night vision like the woman before him, but his other senses were not lame despite his glass of wine. “ **You are mistaken. I-** ” Her throat cleared as she jerked her chin to the side, looking away at something she’d imagined on the horizon — a convenient distraction. “ **I am too large to dance inside the ballroom. My tail would bump into people. Besides, it is far too crowded. You are welcoming a hazard by gathering everyone in one place so defenselessly.** ” 

A slow smirk pulled at Seteth’s lips, mind slightly encouraged by the liquid he’d consumed. He usually disliked the feeling, but tonight it was assisting. “Then out here. It is simply a dance. I distinctly remember an obnoxious version of you attempting to rattle me with proximity when we first met. Your actions were much bolder than a dance invitation.” 

It was true. She’d tried to seduce him a time or two, not getting very far due to commands or spars. That was before this odd intimacy had sparked between the two of them. Occasional meetings of glances, handshakes, and healing spurred things along — late-night conversations about life, the Monastery, and each other. To fuck a contractor out of a contract was one thing, but to have been here as long as she had, with the feelings that had grown over time… It was certainly different. 

But The Ashen Demon backed down from no challenge. 

**“Fine. But… not here.** ” Byleth’s gripped his hand firmly, pulling herself up with his assistance. His hand was warm and confident. How many times had she ignored it before?

Her wings burst from her back, slipping through the cuts in her jacket to unfurl completely. She gave Seteth no warning as she grabbed him tightly and took to the skies. The confidence from earlier faded as his arms vice gripped around her, unwilling to fall from such heights. “ _Ah!_ Byleth -”  
  
“ **We are not going far.** ” With an extra pump of her wings, they gained altitude until they were on the roof of the ballroom itself, the moon framing their silhouettes as they landed. The music was below, still within earshot despite the thick stone. “ **Forgive me if I would not like to be caught off guard on the ground.** ” 

Given a few seconds to settle his thoughts, Seteth straightened out his robes. He was used to heights, given his fighting style, but surprise flights never did sit comfortably with him. “It is a smart, strategical move.” Leave it to Byleth to think of defense at a time like this. She was beginning to sound like him. How the tables turned. “How familiar are you with dancing?” 

Byleth’s hand slipped into his, the other resting on his shoulder comfortably. In a professional waltz, fingers would have been extended, heads back, and angled… Seteth did his best to avoid critiquing. “Familiar. Excellent.” 

Seteth could not deny the atmosphere that clung to them, a… tension that he could not quite place, unlike their forced, contractual bond. This was easier. A bit taboo, but easier. He couldn’t fight the rising heat that reached the tips of his ears, threatening to spill over into his face as they waited for their cue. As displeased as he was with his own unease, he took pride in knowing that Byleth seemed to be flustering about, similarly to him. Her steady hand in his gave him confidence. 

As the music started up for the next song, his hand moved under her arm to rest against her shoulderblade. While the pace was a bit quicker than he’d expected for a waltz, Byleth’s feet worked in tandem with his as they began. He kept the steps simple, seeing what she knew. When Seteth began the turns, Byleth’s grip on his shoulder tightened a bit, riding the momentum as she stepped closer. Impressed, he grinned down at her. “Tell me, where do Demons learn to dance?” 

He dropped her into a small dip, watching her tail arch out to the side as she looked up at him from below. “ **I learned from my father and his court. Cannot have the future queen of Demons bested on any battlefield.** ” 

“Dancing is not a battle, though.” Seteth pulled her back up as the music continued, preparing to spin her. His head pulled back to avoid her horns as she turned beneath his arm, pulling out to the side so that their arms were now extended. Her free hand reached into the air beside her with the ebb and flow of the music before quickly turning like a wound top back into his arms. Their footwork continued, bodies close. 

“ **Is a battle not choreography? The shuffle of feet, the pounding of one’s heartbeat in-ears, the dance of blades and claws back and forth? No, dance can be a fight. There is just no clear winner.** ” Their waltz continued, hands clasped as they began to explore the full dancefloor of the roof. Time grew, as did the area they danced in. “ **Besides. Both make you feel alive.** ” 

_That it did._ Seteth couldn’t argue with that logic. “Very true.” The murmur was lost to the night as they finished the song in silence, the music slowly tapering off. As soon as it had concluded, he let go of Byleth and cleared his throat. “You… are talented.”

“ **Thank you.** ” There was something that hung in the air. Something unspoken, but Seteth wasn’t sure what. 

“W-Would you like to continue? It has been a while since I have had an adept partner in both a training ring or a dancefloor.”  
  
“ **Likewise.** ” She narrowed her eyes, looking off to the side, over the edge of this particular section of the Monastery. Her slitted pupils peered into the dark as if making sure nothing was nearby. Always on edge, ever vigilant. Was this how Seteth appeared to the others? For them to be so different, there were many similarities. “ **... Very well. However, if we are to continue, I would prefer not to continue battering you with my armor.** ” Clawed fingers began to tug at leather straps, removing the armor on her arms, shoulders, and legs. Her tail pushed them off to the side, leaving her in only her jacket and mended clothes. It was quite a feat of trust from the Demon to put herself in such a situation, distracted and without protection. Was this not the very thing she chastized those below about? He buried the thought, thinking it too close to a complaint. “ **I am a more appropriate dance partner now.** ” 

Seteth’s heart pounded in his chest. Exertion, no doubt. There had been a good bit of spinning within the previous song, so he was not surprised to be relatively winded. _Surely, that was it._ “While the armor didn’t completely hinder, I believe this does make it a bit easier.” His smile was warm as he straightened up for the next song. The first had been quicker, so this one was a bit slower to make up for it. When Byleth approached him and took his hand, his face felt hotter. Was he imagining the skin darkening on her cheeks as well, or was the low light playing tricks on his vision?  
  
They swept themselves into the music, a slow waltz made for elegant spins and dancefloor exploration. Unhindered by armor, Byleth could press close for smooth turns. At least, that’s what she told herself. _Sure, that was it._

Raising an eyebrow, Seteth began to guide them through more advanced steps, curious if she would be able to keep up and follow. It was easy to forget that the being in front of him was thousands of years older than he. Of course, she would match him beat for beat, cheek to cheek.

Outside, framed by the giant moon and the array of stars, the torches down below casting shadows against the backdrop of Garreg Mach… Seteth couldn’t help but enjoy himself. His hand held Byleth’s carefully, the hand on her waist slowly relaxing as he and his partner found their rhythm. The first had been a test of skill, but now, it was as if they were working in mental sync. Byleth had taken to focusing on his cheekbone or off to the side as one would do in a traditional waltz, but occasionally he would catch her making eye contact only to smirk, roll her eyes, and turn back away. The constant thudding in his chest, he eventually decided, was due to the seals and their closeness. Even now, locked in the other’s arms as they danced, the seals were glowing with a pale light. 

The Priest began to back up, Byleth catching the cue and spinning so that her back was to him, arms raising as the footwork increased. His palm supported the flat of her back, her free hand extending clawed fingers into the air by her side. When the bridge of the song threatened to crescendo, Seteth pulled at her, spinning her back into his arms as the music swelled to a crest. The powerful rush of the chords took over, exploding into emotion as their eyes met. It all but stole the breath from his lungs. 

Neither of them looked away, muscle memory taking over as the pair swayed slowly, luxuriously. Moved by the music, Byleth’s hand moved a bit higher up his shoulder, nestling close to the curve of his neck. He skipped a breath, almost fumbling his feet. His distracted smile betrayed no frustration over the almost-misstep, her slight smirk unwilling to dislodge for teasing. 

“With skills like this, I am surprised there is not a line for your hand at these bloody events of yours.”

“ **There are. Who do you think causes the mayhem? If they cannot beat me, they cannot dance with me.** ” 

“I look not a gift horse in the mouth.” The weight behind her words carried more than just their purpose. There had to be something beneath them, locked away. Did he wish to dig?

Their push and pull, the spin and extends, everything was fluid as far as traditional dances went. 

Step, step, step. “What you said before. No Demon has caught your eye in _two thousand_ years? That is a long time of solitude.”

Step, step, step. “ **You are correct. Time should not be a factor when settling in matters of the heart. Or sparring partners. Or adept dancing partners.** ” 

There was a rhythm to it. Were her _ears_ flicking at every start of a measure? Every detail, every blink, every moment, made him feel closer. Nearing the end of the song, he elected to finish as they had earlier: a spin and dip. He twirled her, free hand caressing her cheek before it flitted out and away from him. Their gazes locked once more before she came spinning back. The warmth of her rough hand met his once again, practiced and concise, while his arm returned to her back.

With as much grace and strength as he could muster, Seteth dipped her completely. Instead of arching her tail off to the side, Byleth wrapped it around his leg while he glanced down to memorize every feature of her face. Time slowed to a stop; the world around them paused, so the moment was lengthened if only for a few seconds. In this peaceful state, not even the torchlights flickering below made a sound, their flames frozen in place. The band was at a standstill. Just their heaving chests broke the silence, exasperated breaths coming out in wisps of vapor in the chilly air. 

Seteth could hold this position a while, especially with the assistance he was receiving from her tail. Time didn’t need to be stopped for him to figure out what he wanted to do, though - whether the wine had any say so or not. Her golden eyes, her ashen skin in the moonlight, this whole experience - the sigils between them glimmered brightly as Seteth cleared his throat, chests almost touching. In any other circumstance, he would’ve made a comment about - oh, something. Anything. But he felt at a loss for words. There was something unspoken that desperately needed to be said. 

Whenever he tried to open his mouth, no words came out — no _Demon in two thousand years._

 _What about a human_?

Actions spoke louder than words. With everything that he knew and believed to be a lie, the only thing Seteth could rely on was what he felt. What he felt was _alive_. She was right. Dancing was a battle in its own right.

Building up the last bit of courage needed, Seteth lowered his lips to Byleth’s, feeling like he had just stopped time as well. 

**Notes for the Chapter:**

> THERE IS A SETLETH FANZINE CURRENTLY IN THEIR INTEREST CHECK - GO CHECK THEM OUT [ Setleth Fanzine ](https://twitter.com/setlethzine/status/1221195052959051777)
> 
> Thank you so much for all of ya'lls support. I'm super humbled by this community and you guys make me feel so awesome about this fic <3 I hope it brings you as much joy as it does me.  
>    
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	11. Run

**Summary for the Chapter:**

> Seteth has been running from his problems. 
> 
> Byleth is getting tired of it. 
> 
> Flayn, Felix, and Claude have their own opinions on the matter.

Moonlight illuminated the hallway as Byleth slumped, resting the back of her head against the outside of Flayn’s door with a sigh, horns scraping the thick wood in the silence of the hallway. It was early in the morning, the sun nowhere in sight. It had been hours since the Ball had concluded, and she was locked out of Seteth’s room. 

Well, not _locked out_ , per se.

_[Byleth’s eyes widened when Seteth’s lips connected with hers, a ripple of surprise all but ceasing her magic. The flames from the torches below crackled to life, music changing to a new song as the world began to move again. Only they remained still, almost frozen in time before Seteth pulled away, staring down at her with pink cheeks.]_

_Bah._ Another wave of irritation pulsed off of her, the Demon crossing her arms in discontent. She wanted her nest and blankets next to the window, not sleeping out in the hallway because The Priest was having whatever crisis he was working through. The moment had been memorable, but Byleth couldn’t figure out what she did wrong. All she could feel between their bond was anxiety before Seteth had eventually fallen asleep. She wished that she could have been gifted the same fate. Even now, despite hours of patrol and their dancing, sleep eluded her.

_["Byleth, I-” He murmured, breaking the silence while the band below spun another waltz. His arms were sturdy around her, chest heaving as he caught his breath. She was so close. It was hard to pay attention to the pace of the song, given the roar in his ears. They were red, like his cheeks, like the trim on her belt, like the blood that had stained his fingers when he healed the arrow wounds._

_Like the color of the flags he was raising around himself._

_The sudden rush of anxiety almost made him drop Byleth, pulling her to her feet and shaking her tail off of his leg with a nervous cough.]_

“Byleth? Is that you?” 

So preoccupied with her thoughts, Byleth had neglected to check inside the room to make sure the young girl was _present_. Flayn looked at the Demon sleepily, a tiny glass of water in her hands as she padded back from the washroom. Her curls were frizzy, messy, and unkempt from at least an hour or two of sleep. She must’ve slipped out to use the bathroom before Byleth appeared. Mistaking the silence for Flayn sleeping was an error she wouldn’t repeat. 

“ **I am guarding the rooms. I did not wish to disturb your father by coming in late.”** The lie slipped quickly enough from her mouth, the same guilty lips that were pressed up against her father’s earlier. 

The tired girl rubbed at an eye, taking a lazy sip of water. “Would you like to come in? I can stack some stuffed animals for you. Or you can sleep with me if you want!” Byleth shuffled over so that Flayn could open the door behind her and return to her room. 

Something more comfortable than the floor _would_ be nice, but not at the expense of bothering Flayn for it. “ **I am fine out here, but thank you.”**

“Aww, okay. Come in if you get lonely.” Flayn’s free hand patted one of her horns before she practically slept walk back to her bedside, crawling under the covers and passing out immediately after. Byleth doubted that the girl would remember the conversation in the morning, but the sincerity still stood. The young child was a precious gift among strange feelings. With the door closed and everything still once more, Byleth returned her head to the cold surface before closing her eyes as she attempted to let sleep take her. 

_[“_ **_Is there a problem_ ** _?” Byleth’s eyebrow raised as Seteth backed up, peeking over the side of the roof to check the corridors below. He’d started to sweat, and anxiety pooled at both their bellies, though it was hard to tell who it was stemming from._

_“No problem, no, I just need to return to the Ball to check on Flayn, I believe I’ve given her enough time by herself…”_

_Byleth’s eyes narrowed. He’d lost his nerve. The confident, sophisticated man who’d waltzed her into a momentary stupor was looking for any excuse to run. Perhaps she’d chuck him off the side, let him return to the party he so desperately wished to lose himself in. Her wings formed, flaring open with a loud, leathery smack. “_ **Let us get you back down there, then**." _]_

Byleth wasn’t sure what she expected. These feelings of irritation and disappointment were obnoxious at best, but the green-haired oaf had no interest in speaking at the moment. Steeling her resolve, she decided she would force an answer from him tomorrow. It was the least he could do - she thought, smugly - for almost dropping her. Worst case scenario, she’d get to watch him squirm with discontent as he fessed up to the kiss. It was no skin off her back; it had been a pleasant experience. The immediate behavior after... that was what insulted her. 

Attempting to ease her frustration, Byleth closed her eyes and guarded their hallway until sleep claimed her. 

_\---_

Tomorrow came and went.

Seteth was still avoiding her.

Seteth had been avoiding her for days. 

While it was easy for her to track him down, getting answers from him proved difficult. He was always in a meeting, still rooted in paperwork, or consistently in a class. Byleth knew this dive into work was intentional. 

Byleth also knew she wasn’t going to barge in on an important meeting or a class to make things worse. 

Without contact with her contract holder, she was rather aimless. There was only so much she could do to fill the time in her day. She’d taken it upon herself to explore the rest of the Monastery, giving the Cathedral a wide berth, and milling about with the few students she’d formed any bond with in the process. As much as she wanted to go beyond the Monastery walls, the tug of the seal kept her near Seteth unless he specifically allowed it. Given how _busy_ he was, she doubted that was a possibility. Getting near him for an answer of any sort was difficult. The moment he saw her around, he turned on a heel to walk in another direction. 

_Men._

*Ting!*

She didn’t mind second thoughts. Though the scent of wine was evident, he was not even remotely addled, and yet still, it was a bold move. She respected him for it. Humans had an unfortunate tendency to dance around what they needed. Claude was good at it; he could work his way around a conversation and glean as much as possible while giving away hardly any details. Seteth was apt at it as well. It was the moments he was bold that drew her to him: the way he’d faced her head-on, and how he’d dived into a kiss with a Demon.

No. 

It was the _fleeing_ and _avoiding_ that infuriated her. Forced to stay somewhere else to avoid Seteth’s waves of anxiety, she missed the little corner she’d made a temporary home with a fluffy nest. After the second day, her resolve had cracked, persuaded into a den of stuffed animals at the end of Flayn’s bed where she could curl up and keep watch. Flayn was delighted with the idea of having _sleepovers,_ whatever those were.

*Ting!*

“Am I boring you?” Felix’s exasperated sigh interrupted her thoughts, thrusting his sword towards her with precise movements. Byleth, previously lost in thought, deflected the blows with her tail as they darted around the training grounds. Despite Felix’s best efforts, she could close her eyes and avoid his attacks with ease. Perhaps the lack of banter had tipped off the teen?

“ **No. I have a lot on my mind**.” She replied, eyes back to him, appraising his stance like usual.

The answer didn’t satisfy Felix, face twisting into a sneer. “Distracted minds get you killed on the battlefield.” He lunged forward, sword form perfect, albeit predictable.

“ **Hmph. Something we can agree on.”** A quick lash of her tail disarmed him again. “ **Good thing I’m only fighting you then.”** The sword clattered to the ground and slid away from the student. “ **You’re** **too predictable in your stance. Try again.”**

Felix gripped his hand in frustration before sighing, tucking a few stray hairs back behind his ear while he worked on a sore spot between his index finger and thumb. Byleth made a mental note to be a bit more gentle with the disarms. “What kind of problems bother Demons like you anyway? You have strength, and that’s all that matters.” 

For someone so sharp in combat, he seemed relatively one-track minded. Still, he was the best opponent -outside of Seteth- she’d found here so far. At least he was learning on the move. “ **Dumb ones. Tell me. What would cause a human to flee from a problem?”** She reached for his training sword and tossed it back to him, moving to resume their spar. 

The sword rolled in his palm as he adjusted the grip. “Fear. Cowardice. When people don’t know how to handle problems, they run from them.” It made sense enough. 

“ **Keep your elbows close to your body. Less of a target, unless you’re** **thrusting**.” Felix’s position shifted as the Demon spoke. “ **And** **I guess that makes sense.** **I wish humans were more straightforward.”** She grumbled, sidestepping the teen’s first attack, deftly bumping him in the back of his head with the end of her tail. Her scales matched the hue of his hair, the two getting lost in one another moment before he stumbled forward. 

“If someone has a problem and it’s with you, I don’t blame them for running. Seteth and The Archbishop are probably the only people that could best you in battle. Sometimes a tactical retreat is necessary.” Though his words were relatively wise, Felix charged Byleth once again, receiving another tail thwap in response. _A tactical retreat?_ Perhaps that was what Seteth was doing. Reamassing his defenses until he had a plan of attack. There was value in an idea like that, though, as a tactician, Byleth wondered if it were truly necessary. It wasn’t like he was facing down a dragon. 

Well, it wasn’t like he _knew_ he was facing down a dragon. 

Byleth sparred with Felix a little longer until the young lion had class. “ **You are getting better. Thank you for your human insight.”**

Felix shrugged it off. “Whatever helps me get stronger.” He was a man of few words and vacated soon after, leaving Byleth alone in the Training Grounds once again. _Hmph._

_Men._

\---

She could see Seteth’s green hair through the window of his room, high up on a corresponding Monastery tower as she flew about the Grounds. By the time she’d circled again, the curtain was closed. 

_Bah._

Her minor waves of irritation must’ve reached Seteth, because crashing waves of anxiety were the response, threatening to throw her off her flying course. Using her hands to grab onto a balcony, she whipped around so that she was crouching, wings folding on her back as she settled on the stone architecture. It wasn’t unlike what she’d been feeling from him the past few days. Anxiety, nervousness… Occasionally there was a sliver of something warm, but it was like looking for a match’s flame in the middle of a snowstorm. All of the emotions that had once battered her seemed to move to him as the situation changed. 

So, she was forced to keep herself busy. In fact, she had a _schedule_ to hold today. Lifting her chin to the breeze, she smiled slightly before jumping back into the air, wings keeping her aloft to glide towards the gardens.

\---

Flayn was sitting on a bright green blanket, a basket set in front of her while she started sorting out delicately wrapped foods. Claude was lounging in the grass next to her, the two passing the time with idle conversation. They were waiting for Byleth, spotting her rather quickly as she approached in the sky. Her keen ears picked up on Flayn’s excitement, slowly flapping her wings to land gracefully on her feet. “ **Hello, youngling.”**  
  
“Byleth!” She beamed, cheering with her little fists pumped into the air. Byleth’s irritation seemed to melt away whenever she looked at the cheerful child: it was challenging to be upset around her. Even Claude’s usual smirk was a genuine smile around the energetic girl. 

“Ash, joining us on this lovely afternoon?” He sat up from the grass, giving her a quick wink. The Demon settled next to Flayn, gently tousling a large curl with the fluff of her tail. 

Flayn giggled and nodded, pushing the small piles of food towards the gathered attendees. “Yes! We’ve been best buds the past few days. I invited her along.”  
  
Claude raised an eyebrow, intrigued. “Oh?”  
  
The Demon knew what he was doing. Claude was _impressively_ perceptive. Perhaps his opinion on her current matter would be useful. Their child friend had no way of knowing she was being milked for information, so she was a bit easier target than his classmates. “Yes! And she’s even been guarding the door for me at night.”  
  
“ **What kind of food have you brought, Flayn?”** Byleth’s interjection steered the conversation away from her current sleeping situation, hinting to Claude that now was not the time. Sandwiches and apples were dutifully passed out, a shiny, green apple for Byleth while Flayn moved to nibble on a red one. Claude rubbed the yellow apple against his uniform before taking a bite. 

“Byleth, could you…?” The young girl held out her apple for Byleth to take. Leaving her own sandwich halfway out of her mouth, Byleth extended a claw and began a slow, methodical process of peeling the apple with an absurdly long, curly strip forming. Once de-skinned, Flayn took the apple eagerly and began to eat while the Demon dispatched of both her sandwich and the long skinny strip in hungry gulps.

“So, staying with Flayn? Everything okay with-?” Claude pointed to his chest, quickly brushing a bit of grass off his uniform to mask the gesture. Byleth rolled her eyes, looking over at Flayn lazily. While the child was cute, Flayn was also far too preoccupied with singing a song to her apple to listen to their conversation. Claude shrugged. “Hey, better safe than sorry.”  
  
Byleth shrugged as well. “ **I am being avoided. I thought it best to keep a distance until I can get answers out of him.”** The Demon felt a tug at her shirt before Flayn held out her sandwich. The crust was still attached. Using her claws, Byleth began to remove the ends of the bread. 

“How long?” *rip rip*

“ **Almost a week.”** *rip rip*

“Wow, that’s… wild. Alright, fair enough.” Claude watched Byleth hand the sandwich back to Flayn, careful not to drip any of the grape jelly that threatened to slip out. 

His surprise was disheartening. “ **So this is not a common human behavior? He is just running from a problem. How can I make him talk to me?** **I want my nest back, and I rather enjoyed his company.”** She popped a few pieces of the crust into her mouth idly, chewing for the distraction. 

The next reply wasn’t from Claude but Flayn. “My dad can be a bit stubborn. Sometimes you just gotta make him hear you. He gets so caught up in his head. I don’t think he hears anything else but deadlines. Once, I think I heard him recite his calendar in his sleep!” The knowledge was amusing, but Byleth wondered how useful it was. 

She couldn’t help but be impressed. “ **An entire calendar**?” 

“Well, the appointments on the calendar, at least. He was pretty busy that month and dozed off while we ate. Oh, Byleth, can I get a little more help?” The Demon didn’t hesitate to hold her hand out to cut something else for Flayn, still looking at Claude as she did so. A few pieces of chocolate dropped into her palm. “I need some help eating this, would you mind taking a few of these?” 

The sickly sweet smell filled her nose once again, the pieces of candy cold in her palm. “ **Thank you, Flayn. I will happily assist.”** The tip of her tail flicked back and forth, pleased as she tossed them into her mouth. 

Claude grinned at the exchange, surprised Byleth wasn’t asked to cut something else as well. “Well, Flayn does have a point. Perhaps you need to shake him out of whatever’s got him tied up. I owe you after that all-nighter you helped me pull for my Faith class, so lemme give you some more advice.” 

Her nose wrinkled in confusion. “ **Claude, I did none of those things.”**

He waved it off with a hand. “Doesn’t matter. So, here’s what you’ve gotta do…” 

\---

The only thing that greeted her at the top of the staircase to Seteth’s office was another closed door. Byleth couldn’t help but feel it was more metaphorical than anything else, all but ready to bust the damn thing down. It had been almost a week: it had to stop. It was _pathetic_. He couldn’t keep dodging her for the rest of eternity. This had to be settled at some point, and Claude had given her excellent advice. When in doubt, lock him in his room until he spilled ‘the beans.’ Byleth could not smell any food within the room, but perhaps it too was a metaphor.

She tested the lock, pleased when the door clicked open without protest. Seteth looked up from his desk, immediately flinching when he saw the Demon’s golden eyes staring blankly in the doorway. “ **We need to talk**.” 

Seteth’s hands fumbled for his papers as he stood, shooting a quick glance out the window. “Oh, i’m sorry Byleth, another time, I was _just_ on my way to a meeting.” 

Her clawed hand slammed the door shut behind her, sturdy body leaning against it. The perfect deterrent if his previous behavior was anything to go off of. As much as she tried to avoid being bitter, it wasn’t working. “ **I think you misunderstand. We’re talking.”**

“Byleth, let me out. I have a lot of important things to get to-”  
  
Her lip curled slightly, showing off white fangs. “ **Shove it.”**  
  
His lips pressed into a thin line. “There is nothing to talk about!” He insisted, not managing to meet her eyes.

Byleth’s impatience got the better of her, a sound of disgust leaving her mouth. “ **This is pathetic,** **_Priest_** **.”** There it was again. Oh, how Seteth hated the way she spat that. The words twisted in his gut like a knife, the tone hitting its mark. “ **It was a kiss, it’s not like you fucked me cross-eyed.”**

The crude nature of Byleth’s statement caused a flush to grow on his cheeks. He cleared his throat, grip tightening on the unfortunate papers in his hand. “Keep your voice down! That language-” 

The Ashen Demon wasn’t finished, holding a clawed finger to his mouth without much regard for his personal opinions. The gesture shut him up, the last of his words dying in his throat as he glanced down at the clawed appendage. “ **Continue in this manner, and I will not be able not to feel offended. Do not be ashamed of your bold gesture** **. Take pride in your actions, instead of running away like a scared kit. This behavior is just… embarrassing.”**

 _Wait…_ Seteth could feel the rough pad of her finger against his lips, years of battle accumulated at the tip of a digit made to destroy. _Ashamed_? The waves of frustration and irritation weren’t from the kiss itself? He’d spent the past few days, almost every moment post-dance, fighting through his thoughts and emotions. When he caught wafts of hers, they were always pointed and cross. It never occurred to him they were for reasons outside of his assumption. “Are you upset at me for… _running_?”  
  
Her finger lowered, arms crossing as she glowered. “ **Yes. It’s infuriating.”**

The Priest paused, gears turning behind furrowed eyebrows. “And, not because of-” Leave it to him to make the situation worse on a completely baseless premise.   
  
“ **No, you fucking youngling.”** The exasperation shared between the two was astronomical, both immovable forces attempting to find common ground once more. With Byleth still blocking the door, Seteth didn’t have much of a choice as he ran a hand through his hair, frustration taking root. 

When he finally found the words, they were heavy and tired. “I guess I did not know how to progress. I did what felt right when I was in the moment. When I was out of the moment, I… didn’t know what to do after. Would you have known what to do?” His earnest reply shocked her, but it was not evident in her flat expression. 

After a moment of consideration, Byleth shook her head. “ **No. I refused all previous advances from other entities. Violently.”**

The blunt answer forced a chuckle from him, albeit nervously. The blip of humor amid the myriad of emotions he was feeling helped diffuse some of the tension that had taken hold, allowing him to relax his shoulders _ever so slightly_. “Well, now that I know that information, I appreciate your acceptance and flexibility.” The edge of her lip curled up into a small smirk. 

But then there was silence. 

An awkward

Long

Silence. 

Byleth remained at the door.

 _Goddess, spare us this torment. “We’ve_ found ourselves in a relatively difficult situation, and for that, I apologize. I suppose we discuss where to go from here.” By the flick of her tail and the refocus of her eyes, Seteth could only assume that was the correct answer to begin with. What probably should have happened days before now. The sigil on his chest pulsed. 

“ **Don’t** **sound so enthused,** **_Seteth.”_** She purred. “ **You make it sound like it’s a bad thing. If there’s anything you and your merry band of students have tried to drill into my head, it is not to fight what I feel. Difficult or not, we can at least attempt to… enjoy it.”** Her tail rose to brush against his leg, causing him to utter a nervous, unintelligible noise.

“I-If we’re going to attempt _anything_ -” He gently pushed her tail away with his foot, controlling his rapid heart rate by breathing a little slower. “-I would need it to be… slow. Slow and done correctly.” 

The words confused her, brows furrowing as she stewed on the word. “ **Correctly?** **Slow I can understand, despite your short lifespan, but what do you consider correct?”**

What _did_ he consider correct? Seteth cleared his throat and smoothed out the front of his robes. “Well, like you have denied advances based on your own personal code, I have my own… things that I look for. I want to make sure it feels right.” 

Byleth nodded. “ **That is fair. You are well within your rights.”**

“I’m glad you agree. Time spent together, gift exchanging, experiences shared... “His hand gestured in a lazy circle. “Etcetera, etcetera. I do not believe I have to explain courtship, correct?”

“ **You are correct.”** The Demon still sat in front of the door, thick tail now by her side. The headway in the conversation had been fruitful, but Seteth couldn’t shake the feeling she was still waiting on something else. When he stepped forward towards the door, her hand reached out for his wrist, stopping him just shy of the knob itself.

Her brow furrowed as she worked for words, face growing hot. “... **Then let’s try it.”**

Seteth’s eyebrows lifted slightly, unsure if he’d processed what she said. It was one thing to sneak a kiss on the rooftop, but another to pursue affections. It was entirely another thing beyond _that_ to attempt this between their two species. Though, Flayn’s bloodline served as an example: it had been done before to an extent. “Really?” 

“ **Tch.”** She turned away, cheeks darkening in their own fashion. “ **You ought to know by now. I do not say things I do not mean. The kiss was not unpleasant, I am physically attracted to you, and these new emotions are worth exploring in the company of someone I** **respect.”** After a beat, she added hastily. “ **Correctly, as you say.”** Her fingers let up on his wrist, releasing his hand to exit if he wanted. Golden eyes focused on his now, encouraged by the personal acknowledgment of her emotions. Seteth was almost impressed, silent as his green eyes locked with hers. The tension that had thrummed between them was fading, instead replaced by an electric buzz that hummed through Seteth’s veins. 

Pursuing Byleth would be difficult, and honestly, he was not sure what his true intentions were a few days prior, but this was the reality they had to work with at the moment. As much as his academic mind told him it was a terrible idea, the heart always sang a different tune. In the haze of the Ball, with the moon framing their dancing silhouettes, everything seemed perfect. Steps were in time, the stars were shining, and in their seclusion, Seteth felt secure. But it was merely a night, and this was reality. 

He couldn’t help but wonder how reality would change if every day were like that. His soul was not being signed over for any heinous purpose, and his body was not being given to the enemy Legion. No, they were two adult individuals just as lost in these emotions as the other. It couldn’t - no, it wouldn’t - hurt to try. 

“I agree.” Seteth’s hand lowered back to his side, focus pulled away from the door once more. “But if at any point either of us feel uncomfortable-” Flashes from the memory of Byleth’s claw tip gently riding up the side of his body sent a ripple across his skin, thankful that he wore enough layers to hide the gooseflesh that formed at the thought. “-or the pressure is too much, or-” Byleth looked as though she wanted to say something, but remained silent. “- we decide that it is not working, communication is of paramount importance.” 

“ **Relax, please. I will not do anything you do not want me to do, especially now. It was one thing to embarrass and annoy you. It is another to… well… Besides. I am a Demon, not a monster. What do you want?”**

 _What do I want_? Seteth’s eyes searched hers, rifling for the answer as if it would be there. There was no magic solution in her golden eyes, but they did hold promise. There was always something just shy in them that he couldn’t quite reach, always pulling his gaze back to her, even when he probably shouldn’t. It was a dangerous game they were dancing around. His hand reached forward, and Byleth moved so he could reach the doorknob, but stopped when his fingers wrapped around her hand. He gave it a light squeeze. “Slow.” 

His palm was warm and gentle, a feeling Byleth missed the moment his hand vacated her grip. The surprise gesture of affection seemed to solidify their strange agreement. “ **Slow.”**

\---

Seteth hadn’t been lying about a meeting, running a bit later into the night than he had anticipated. Byleth was curled up on the nest of pillows she’d made, covered up by a blanket as well. Now that things were settled between the two, she dared him to shoo her out. When he entered the room, he slowed, setting his papers off to the side before pinching the bridge of his nose in fatigue. The Demon’s head popped up over the side of the bed, observing him. Her chin was resting on the mattress, tired eyes following his movements as he got ready for bed. “ **They kept you late.”**

“Yes, apologies. I was late to the meeting, and it ran over after a certain Demon cornered and bullied me until I agreed to her romantic advances.” He was more at ease now than he wasn’t in his office. The talk certainly helped. The lack of an angry Demon stalking outside his door also helped. “My life was in danger.” 

Byleth’s scoff threatened to echo through the bedchamber, mirth dripping from her words. “ **How forward of her.”**

“I am very oppressed.” He replied as flatly as possible despite the slow, creeping smirk that threatened to break their banter, removing his outer robes with a sigh. “But, I guess there are worse fates.” When he moved to slip under the covers, he took note of the low, red light that emanated from his chest. Byleth continued to watch him get comfortable, keenly aware of the sigil shining on her own skin. 

“ **While I am not sorry I made you late, I apologize you returned late. I thought you were coming up with another excuse. Everything else was your fault.”** The Demon admitted, yawning sleepily. “ **But... i** **f they have a problem with it, you can always send them to me.”** Her yawn accented the sharp canines in her mouth. Seteth shuddered to think what would befall someone who crossed her. He’d seen the underground passages she rescued Flayn from. 

“That won’t be necessary. However…” He trailed off, looking towards the window. The content expression on his face faltered slightly. “It is going to be rather cold tonight, and I was freezing on the walk back. Is your nest going to be warm enough?” he settled in his blankets, pulling them up to his chest as he shifted around.

Byleth pushed the blanket above her head, covering her horns so that he’d see she was wrapped up. “ **I am fine, but thank you for the concern.”**

He watched her a few more moments before nodding, settling into the covers and rolling onto his side to face her. A reasonable length of the bed separated them, but even now, Seteth could feel his heart race. There was not much light in the bedchamber, but her eyes still seemed to shine in the moon’s low glow.

The polite, gentleman-esque action would have been to invite her into the bed, but he couldn’t bring himself to do so. _Slow. Correctly._ If Byleth minded, she certainly didn’t show it. Instead, she yawned once again, letting her teeth click shut with an audible snap.

 **“Flying**.” 

Seteth raised an eyebrow. “Flying?” He propped his arm up, resting a cheek on his hand, curiously. “What about it?” 

She leaned back against the wall, pulling the blanket close, much like Flayn did when wrapping up. Her tail then wrapped around it snugly, tying the package up in a scaled bow. “ **It is one of my favorite things to do. To share an experience, it must mean something, yes?”** Seteth’s silent nod urged her to continue. **“I** **want to go flying with you.** **Your wyvern would do. I do not need one.”** The suggestion did have its merits. There was always a tactical advantage to getting a good vantage point of the countryside outside of Garreg Mach, but when Byleth put it that way. Her wanderlust was one of the most powerful emotions he felt through their bond, especially during the past few days of little to no communication. 

“I think that would be a good experience to share. What about the free day?” He offered, calculating eyes searching for her reaction. A deep, throaty sound began to emanate from her, vibrating from her chest, hardly muffled by the thick blanket draped around her. It was a low rumble, akin to a cat’s purr. 

Despite her obviously positive reaction, Byleth’s face remained relatively expressionless, her eyes closing a bit more from fatigue. “ **I would like that. I admit I would like to see beyond the Monastery walls and see how the world has changed.”** She pulled the blanket a bit closer around herself, relishing the warmth. “ **And the company would not be so bad, either.”**

He smiled, just a little. “Well, I suppose you could twist my arm. Flying it is.” 

Byleth’s eyes closed, a rare, genuine smile breaking the stony mask she usually wore. “ **I look forward to it.”**

_Do I as well?_

The Demon was wrapped up in a fur-lined blanket, tail wrapped around the outside while her breathing slowed: no armor, no weapons, no defenses. There was no more irritation, no more frustration from being secluded or left out. All he could feel from her was contentment. 

If he were honest, that’s all he felt too. “Me too. Goodnight, Byleth.”  
  
The Demon was already asleep. 

**Notes for the Chapter:**

> THERE IS A SETLETH FANZINE CURRENTLY IN THEIR INTEREST CHECK - GO CHECK THEM OUT [ Setleth Fanzine ](https://twitter.com/setlethzine/status/1221195052959051777)
> 
> I rewrote this four times
> 
> The struggle is real  
>    
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	12. Fly

**Summary for the Chapter:**

> Seteth and Byleth get a taste of freedom when they take a day away from the Monastery. 
> 
> Conversations are had, and affections are explored.

Byleth rarely had things to honestly look forward to, so counting down the days until the Monastery free day was almost torture. A few meetings with Seteth, spending time with Flayn, training the occasional student that wished to spar… There weren’t enough things in the day to keep her preoccupied. Half a week had passed, but freedom still felt so far away. Everything in her body roared for time to speed up.

“Patience.” Seteth would preach, though he could never say it without a slight smirk. Seeing Byleth so eager was borderline infectious. He found himself looking forward to their first foray out together. 

Alone.

Well, Saint counted. But still. 

Byleth's annoyed huff only amused him further. “ **I am trying. Only when things are worth waiting for.** ” Her bright eyes were always glued to the sky, anticipation hardwired into her muscles. She seemed ready to leap out of the window at any moment, eager to drink in the night air and stretch her wings.

Seteth closed the book he was reading, placing it on the nightstand beside him, committing himself to converse instead. “It is only a few days away. Just a few more nights of sleep, and then we will be out there.” He shifted over to the other side of the bed, next to the nest she’d made on the floor beside it.

The Demon huffed, leaning her back against the side of the mattress, almost dejectedly. The tips of her horns pressed against the thick blankets, jutting up slightly. “ **I can only stop time. I cannot speed it up. Perhaps I can practice, though.** ” 

While she spoke, Seteth reached a tentative hand out to touch the ends of her horns, their gold caps removed for ease of comfort. They felt just like ram horns, thick and sturdy ridges that created interesting topography on what would have been a smooth, sleek fork. Byleth didn’t seem to mind. “Yes, but if you experiment with stopping time, wouldn’t it take you longer to get to flying day?” 

There was a decent pause as the Demon considered, the gears in her head slowly clicking together. “ **You make a good point.** **I will avoid messing with time. Making this ordeal even** ** _longer_** **would probably drive me mad.** ” Her eyes closed as she exhaled through her nose, a slow gesture as she preoccupied her mind with someone else. 

The Priest sat up, moving his hand from her horn to her hair, fingers rubbing against her scalp slowly, almost as if nervous he’d hurt her. She leaned back into his touch, a rumble in her chest slowly humming to life. “ **If you keep that up, perhaps I’d be preoccupied until the free day.** ” Outside of the occasional hand brush or tail touch, there hadn’t been much physical contact after their conversation. It had only been a few days, but Byleth was remarkably respectful of his boundaries. It made things easier to ease into.

“If only. A day of no responsibilities would be lovely.” He continued to massage her scalp, watching the Demon’s ears slowly lower and lower as his pressure increased. Curious, he sat up and moved one leg to either side of her shoulders, freeing up both hands for her hair. 

With the double effort, her ears all but dropped entirely, the rumble in her chest full throttle. “ **Around the horns feels best.** ” She murmured, tucking her chin down to expose more of her head. Seteth’s fingers moved to the base of her horns, immediately feeling a difference in the give of her skin: around the horns was tougher- gnarled flesh marred by the growth of the black protrusions. As soon as his fingers brushed against the skin, she melted. 

They continued like this for a while, idly chatting while Byleth controlled the urge to fall asleep as Seteth’s deft fingers worked away her stress. 

After a few moments of silence, Byleth stirred, as if jostled awake. “ **Would you like me to return the favor?** ” She murmured sleepily, eyes still closed as he massaged. 

While the claws would make for an interesting sensation, Seteth shook his head. The chain attached to his glasses wobbled with the gesture. “No, but I appreciate the offer. Besides, it’s interesting to see just how easy it is to see The Ashen Demon unravel with just head scratches. If only the Demon hordes knew her terrifying secret.”

Her jaw set as she snorted, the Demon struggling to show her discontent amid Seteth’s pampering. “ **Be nice. I haven’t been touched like this for at least a millennia.** ” The thought made him pause, fingers stopping momentarily. 

“Millennia?” There was a long wait as he considered. “I guess you have me beat. How do you stand it for so long?” 

The motor in her chest stopped as she looked up, trying to catch a glimpse of his expression. The dangling chain from his glasses bumped into her face, causing her to wrinkle her nose. “ **I am quite a prize. I would not settle for anything less than what I wish.** ” 

The chain dangled near her face again, so she hooked a finger through it and pulled gently forward. Not wanting his glasses to fall off, he leaned forward as well. “Ah! Byleth, my glasses, please don’t-” 

When he was close enough, Byleth lifted up and pressed a kiss to the bottom of his chin, feeling the heat of his skin and the scratch of his beard on her lips. She let go of the chain and Seteth sat up, taking the glasses off so they didn’t end up a casualty of evening affections. “ **You have an early meeting. Best not to be late.** ” She purred teasingly, falling forward onto her nest of pillows. Even in the low light, she could see the color flush on his neck and ears. It was still _slow_ , but she wasn’t going to telegraph _everything_. Besides. He made it far too entertaining.

His fingers brushed against his chin as he watched her settle, moving his legs so she could stretch out on her nest. “Yes, right… meetings.” He'd almost forgotten.

Byleth could hear him shuffle to get under the covers despite having already closed her eyes. “ **Good night.** ” 

“Good night, Byleth.”

\---

It was Free Day. 

It was _Flying_ Day. 

Seteth had already taken it upon himself the evening before to have everything prepared at the stables, saving him a bit of sleep on what was already going to be an early start to the morning. The previous night’s sleep was uninterrupted, though the Priest was surprised Byleth hadn’t already woken him. His curious eyes peered over the edge of the bed, checking to see if she was somehow still asleep.

She wasn’t there. 

“Byleth?” He murmured, raising an eyebrow. A quick glance into the open washroom confirmed she wasn’t in there, either. “Byleth? Are you… hiding?” It was unlikely, but the Demon had surprised him in more ways than one recently. When he received no answer, he set himself to get ready and look for her. Surely she wouldn’t have gone far, given what today was. If their plans were set to change, Seteth wouldn’t help but feel a tad bit disappointed. He’d been looking forward to enjoying the day with the enigma he was tied to, in more ways than one. 

Setting his suspicions to rest, he found Byleth relatively quickly. He’d made his way down to the stables quietly, knowing others were still in bed at such an early hour. The sun had yet to peek over the horizon, which meant they’d be flying with some extraordinary colors in the background once the sun decided to breach. It was in the stables he found her, nestled in the hay with Saint, his Wyvern mount and battle companion, engaged in what appeared to be a conversation. He hoped the scents of the animals and stables were enough not to tip off Byleth to his presence. 

Saint’s throat rumbled, and Byleth did in return, her clawed hand reaching out to stroke a few scales on the wyvern’s neck. He leaned into her touch, cocking his head to the side so that Byleth could reach under a horn. It was there she pulled a small, crinkled scale from his skin, allowing the wyvern to sigh in relief. The rumbles and warbles continued for a few moments, both of their tails flicking idly with the conversation. 

When Seteth cleared his throat softly, both sets of glowing eyes turned to face him. “ **Good morning, Seteth. I was speaking with your wyvern friend.** ” Saint’s eyes blinked slowly, almost cat-like, as he watched Seteth approach. The Priest patted the beast’s hide fondly, running a hand down the dragon’s flank. 

Curiosity took hold as he raised an eyebrow. _Can she speak with wyverns? How interesting._ He supposed the tail was a good enough indicator. “Oh, yes? And what did Saint here have to say?” 

A rare, wry smile. “ **That his name is actually Pebbles, but he tolerates the name Saint, and that you take excellent care of him. I also took care of a folded scale that was causing him some discomfort, and he is now ready and excited for flying.** ” Her hand patted the scales one last time before standing, tail brushing her legs off, a few stray strands of hay gently falling to the ground. When Seteth stepped forward to remove a stray bundle of hay from her hair, she did not shy away. “ **I hope you do not mind, I was too eager, so I have been here with him waiting for you.** ” 

“Of course not. Your excitement is contagious. I cannot help but feel the same.” Though it was not the fault of the bond, that much was certain. Practiced hands grappled at the saddle, beginning to fit Saint -or Pebbles?- into the leather straps. “Are you prepared? I’ve packed food for the three of us, as well as coats in case the weather decides to change on us.” 

“ **How dutiful. It seems you have thought of everything.** ” The glow in her eyes dulled slightly, seeing the magnificent beast before them being fit into straps and saddle, but a warbling rumble in the wyvern’s chest seemed to put her at ease.

Seteth tightened the last strap, testing the give to make sure that Saint could easily move without worry. Byleth didn’t seem to need any preparation, wearing only what she usually did, leaving Seteth and Saint to carry the necessities. Considering she’d be flying alongside, he figured it was for the best. “I do my best. It would be poor if we found ourselves woefully unprepared.” With a nod and a test of the last strap, he stepped back to admire his handiwork, the straps and knots tied to perfection. 

“ **You’ve got quite some experience with binding.** ” The Demon purred, nudging him with an elbow, amusing herself at his deep flush at her implied thoughts. 

He took to fussing over one of the saddlebags instead, unwilling to give her too much satisfaction with his fluster. “Yes. Many years of battle with Saint, er, Pebbles.”

“ **Are you prepared?** ” She inquired, raising an eyebrow at the tidiness of Seteth’s packing. The Priest nodded surely. " **Perfe** -" Byleth paused, ears lowering a bit as Seteth reached for something else. The last thing his hand snagged was his spear, clicking it into place in a makeshift holder of sorts, making it easy to pull out in the heat of battle. While Byleth didn’t think it necessary, it was always pertinent to have a weapon. He was already tied to what was, quite possibly, the strongest weapon on the plane. “ **Excellent. Ready?** ” It was almost cute how eager she was, but if he'd been confined to the Monastery for so long - Wait. He was just as trapped as she was, though by choice rather than by bond. What did that say of his choices? Perhaps he needed this foray just as much as she did. 

Seteth nodded, hoisting up onto Saint’s back with a grunt. His weight shifted, feet sliding into the stirrups on the side of the wyvern, hands nestled at the horn of the saddle for balance. The Demon watched him, eyes following his movements as his hips settled. Her wings flared out, the sound of leather sliding against leather before they pulled taut with a loud crack. Saint rumbled and took a few steps forward, Seteth’s hips rocking to stay aloft with the awkward steps. Once outside, Saint pumped his wings, taking a few lumbering jumps forward to prepare for liftoff. Once he’d gotten enough speed, the quick heaves of his wings were enough to lift Seteth into the air. The ground got further and further away as they gained altitude, Byleth watching from the ground below. Seteth cupped his hands around his mouth, shouting down to the idle Demon. “Are you coming?” 

“ **Hrm.** ” She took a similar stance as Saint, jumping into the air with ease. Her wings lifted her, chasing after the Wyvern rider, hair streaming behind her as the wind rose to meet her face. Seteth expected her to stop so they could fly together, but given a tiny bit of freedom, Byleth rocketed into the air. 

The sheer joy he felt from her almost knocked him off of Saint, amazed at her speed and power as she vaulted above him. The wind from her wings ruffled his hair, and he could just barely catch the scent of the mint tea she was so fond of. “Wait up!”

Byleth spun in the air, wings broad as they cut at the low fog of the early morning, chest rumbling with happiness as she whipped around freely. When the wyvern flew to Byleth’s side, her eyes were wide with emotion, more than he’d seen her express before. Those same eager eyes locked with his, and she _smiled_. “ **Let’s go. Please.** ” 

How could he say no?

\---

The sun was threatening to peek over the horizon, soft rays of light beginning to illuminate half of the sky with deep oranges and purples. Byleth had reigned in her excitement to fly next to Seteth, eyes burning a path ahead as she took in all of the sights of Fodlan's countryside. Seteth found himself staring more often than not, a hand set idly on the horn of the saddle to stay upright. The dew and condensation that had settled on Byleth’s wings left them slick, efficiently reflecting the remaining moonlight behind them. Occasionally she would look over at him, eyes half-lidded in content existence, happy to just continue moving forward instead of stagnating within the Monastery walls.

Walls that would soon be completed. 

Walls that were just another separation of their species. 

There must have been some tell on Seteth’s face, something to tip off his thoughts wandering because Byleth’s eyes flicked down to Saint’s. They both rumbled between one another before the Demon immediately took off towards the sunrise, hands clawing through the air as she picked up in speed. Seteth felt Saint’s muscles tense under the saddle as the wyvern prepared to speed off as well. 

“Oh no.”  
  
The wyvern took off as well, roaring gleefully while Seteth grappled for a hold, unprepared for the sudden speed. Byleth was quick and agile but didn’t fly at a pace that Saint couldn’t catch up to. When they were side by side once more, Byleth was flying upside down, eyes closed. The only tell they’d arrived was Saint’s wingbeats, heavy against the morning air. “ **Welcome back.** **I was wondering where you’d gone off to.** ” 

Seteth straightened himself, fixing his glasses and front of his shirt. “Apologies. I was miles away, but your little race brought me back.”  
  
“ **I could tell. Am I that boring?** ” 

“Hardly. I just cannot leave the Monastery without my thoughts slowly catching up, even on wyvern back.” That bit was valid. Flayn was there. His responsibilities were there. Rhea was there. In all honesty, he _shouldn’t_ even be here, and yet, something about the prospect of letting loose with Byleth, even for a day, was too good to pass up. 

Her eyes were still closed, but the smile had disappeared, a small frown tugging at the corner of her lips. “ **I see. A lot is riding on you.** ” 

Seteth flinched, a pang of guilt making him wince. Yes, it was true, and yet, this was supposed to be something for Byleth. Something for both of them. He cleared his throat and patted Saint’s neck. “No, I am doing the riding.” The joke was simple, and while his delivery fell a bit flat, she tilted her head to the side to look over at him. 

The distaste was clear. “ **Really? That was bad, even for you.** ” 

“You are correct. It is much better than the fish joke, though.”  
  
“ **Take it back - I** ** _love_** **the fish joke.** ” Her tone betrayed no mirth.

Seteth let out a laugh, warm and light as they flew. His hands flew up in front of him in a defensive posture, his smile warm like the sun that continued to peek over the horizon. “Very well, I take it back. The fish joke reigns supreme.” 

The pleased rumble from Byleth could be heard from where he sat on Saint, through the wingbeats and breaths of the wyvern itself. It made him feel content as well. 

\---

Their banter was satisfying - no longer an effort as the two flew along the river’s path. Still, it eventually faded to a comfortable silence while Seteth returned to thoughts of the Monastery. Thoughts of Byleth. Thoughts of whatever this was. What would happen when the walls were fixed? What would happen when _Rhea_ was fixed? This arrangement - temporary in nature - was proving to be a fun experience thus far, their differences behind them for the most part. How _did_ he feel towards the Demon beside him? Seteth was excellent at advising Rhea, coming up with questions to help provoke her thoughts towards a decision. 

He was never good at coming up with the answers himself.

The countryside passed under them, extensive, sprawling farms full of various fruits and vegetables. The thought of food made Seteth’s stomach rumble, and he doubted that Byleth would pass up eating at the moment. However, he wished to get a little farther ahead before stopping for a meal. “Let’s keep flying a bit longer, and then we can stop and eat. Is that alright?”

He looked over at the Demon flying beside him, eyes closed as if in a trance. Her concentration broke as bright golden eyes opened to meet with his, nodding a few times as an answer. 

“Excellent.” 

Time passed for a few more moments before Byleth broke the silence, yawning slightly as she stretched mid-air. “ **Seteth.** ” 

“Yes?” 

Her voice was flat, but not anything out of the ordinary. “ **What is on your mind?** ” 

_Drat._ She’d noticed before. It was only a matter of time before she saw it again. “Nothing gets past you, does it?” He murmured, stretching his arms over his head. “Thoughts of the Monastery. Thoughts of…” He didn’t mean to trail off, clearing his throat to get rid of the knot in the back of it. “Thoughts of us. Thoughts of what we’re doing, and where it goes.” 

“ **Second-guessing** **already?** ” Byleth’s smirk returned, amused at Seteth’s dilemma. " **Seteth, it is not the end of the world. This is not some soul-binding choice you've made. It can end at any time.** " 

Her relaxation made him jealous: how was she so careless? “Not so much a second guess as a… morbid curiosity as to why?” 

A thoughtful chuckle so light Seteth could have imagined it amid the whipping winds hurtling past them left her lips before she began to move. Her right wing tilted down so she could bank to the side, and with a few beats, she was flying above the Wyvern and Seteth with her tail streaming behind her. As she lowered, her hand reached down to ruffle his hair, unsuccessful in her attempt to steal his circlet. “ **Could we not call** ** _all_** **of this a morbid curiosity?** ” Her laugh was infectious. “ **But, if you must know, it was the spar.** ” 

“The spar?” The words fell out of him like spilled tea, incredulously. Their surprise startled him, but only pulled more entertainment from the Demon flying above him. He raised his hand above his head to fix a fluttering buckle on her jacket.

“ **Yes, the spar. You went out of your way to approach things from a Demon perspective. You bested me in a single bout of combat and gained my respect. From then on, it was… little things.** ” She paused, looking down at him only for a quick second before looking forward, happy the angle hid the heat rising in her cheeks. “ **The way you fuss over your youngling, the way your jaw sets when you focus hard on paperwork, or the way you snap quills when startled. I admit, I owe you quite a few, many of them were on purpose.** **But these things slowly built, as did my curiosity.** ” 

It should have been unsurprising to him that Byleth actually had an answer, especially one that put so much thought into the situation. It was difficult to look past the stereotypes of their warring races, but when he did, he saw someone that put just as much thought into things as he did. Perhaps she was a bit more confident with her choices, a bit more lax with her affections, but as they spoke, he grew less and less worried that this was just an experiment. The nature of it was casual, but that was no crime. “Thank you, Byleth. How are you so casual about it?” 

“ **You are welcome. It is still strange, I understand.** ” She banked to the right, moving away from flying above them, moving over to his right side now. Her flying was even and steady. " **We live a long time. Lovers come and go. If it is meant to be, it is meant to be. If not, the time we spent together was worth it if we deem it so.** " 

Seteth’s fingers reached out to touch the leathery wing, now dry from the afternoon sun. “I guess I get so caught up in my thoughts, worries that may or may not come to pass. It is my job to think of a topic from all angles.” 

The Demon held her position, wings locked to let him feel. “ **And no angles match up?** ” By the way her question trailed, it seemed as though she’d caught on to his train of thought.

“Correct.” 

“ **Try this angle, then. Why me?** ” Her eyes shifted back to his with amusement, the inquiry now out in the air between them.

Seteth paused - Byleth was well within her rights to ask such a question but did Seteth truly have an answer? “I… I saw you with Flayn. You shattered all preconceived notions I had about you. I would be lying if I said I was apprehensive, but everything had changed since you arrived. I would never have considered something like this, but… I wanted to try.” 

The answer did not seem to hit the mark, despite Seteth’s nervous mannerisms. Byleth cleared her throat. “ **Yes, but** ** _why_** **?”**

 _Because I find you physically attractive? Because seeing you dote over my daughter made me feel things I haven’t felt in years? What are you getting at?_ “Outside of standard answers, I… don’t know.” He scratched the back of his neck, sheepishly. 

There it was. Byleth's smirk grew. “ **That is my point. There does not have to be an answer. Just enjoy it. It ends when it ends, but until then, there is no crime in letting yourself enjoy something.** ” 

“... Oh. _Oh_.”

It was a revelation. 

She flew in a wide arc around them, under Saint, and then approached Seteth from the side. Wingbeats slowed to match the wyvern below him as she approached the flying beast. Byleth’s foot hooked on top of leather saddle rigging to the side, bracing herself so she could rest momentarily.

In a smooth motion, Byeth slipped in front of the saddle, resting backward on Saint’s neck. The wyvern didn’t seem to mind, thankful for her slow movements to readjust as she faced Seteth, who was surprised at the sudden proximity. He’d slid back to make room for her, the base of her tail pressed against the saddle horn while the length wrapped around Saint’s chest to stay balanced. Seteth’s arm wrapped around the Demon, acutely aware she had no reins to hold onto for staying upright. There was no protest as she wrapped her arms around him as well.

Of course there wasn’t, she’d planned it. 

Their faces were close now, Byleth’s black and golden eyes watching his with interest. As her wings folded against her back, Seteth became aware of the warmth he felt with her body pressed against his. Up in the air was typically a cold experience, but Byleth fixed that, at least temporarily. While he wouldn’t suggest it for battle or long transport, it certainly had a few benefits. He would’ve heard his heartbeat roar in his ears if it weren’t for the rumble of both Wyverns against him or the winds they flew through.

Byleth closed the distance between their lips for the first time since the Ball.

It was different from their stolen moonlit night, a warm kiss both parties were expecting, and one neither technically fought against. Everything about Byleth was warm, her lips and chest pressed against him as his own grip tightened around her. Their mouths moved in tandem, a different kind of dance, as the world sped around them. There was no need for magic this high in the air, no reason to stop time when they were perfectly capable of stunning one another just as effectively. 

One of her hands rose to his cheek, clawed thumb brushing against some of the stubble at his jawline. The simple gesture made his skin tingle, surprising the Priest at just how touch-starved he truly was. He thought he had denied any touch out of fear of being inappropriate, or ungentlemanly. The fire it stoked in his veins was a long-forgotten feeling, though with Byleth this close it threatened to burn him from the inside out. Seteth now knew he’d been denying himself because he’d been unsure. Scared of the intimacy it brought. Afraid of what it made him want, his pious and devout mind clouded by selfish desires, rather than to his work.

The pace of the kiss increased, Seteth progressing slowly as he dared to explore. When his tongue brushed up against her lower lip they parted immediately for him, granting entrance with a pleased purr. The Priest obliged, tongue sliding up against hers with a languid murmur. Byleth cocked her head slightly to the side, returning the affections with matching enthusiasm while the hand on his face kept him close, encouraging him to continue. The world passed around them, but there was nothing to interrupt them in the sky.

His heart leaped to his throat, threatening to suffocate him if he didn’t manage a few breaths, lost in emotion.

The Demon pulled away slightly, gauging Seteth’s reaction almost coyly, lips leaving his to subject him to the cold of the skies once more. His left hand let go of the leather straps, rising to her face to pull her back. With his eyes closed, all he could do was feel for her skin. As her hair whipped around with the wind, his hands grappled for the first thing he could grab. 

Seteth expected to feel smooth skin under his fingertips, though his experience was years behind him. Instead, two things happened. First, his fingers brushed against fur: her ears. The sudden contact against them made her flick them back in shock, the touch making her shiver — _sensitive ears._ Seteth made a note of the discovery, committing it to memory for later.

The second thing was that his fingers had curled around her horns, using those to pull her back into the kiss. The enthusiasm of the yank surprised him but elicited a pleased grunt from Byleth as their lips met again.

It wasn’t until Seteth realized he was gripping her horns with such force it was causing his hands to hurt that he tumbled back to reality. 

Byleth felt his focus shift and slowed down, pulling at his bottom lip with her teeth momentarily before letting it flick back into place with an amused huff. They both worked to catch their breath, keenly aware of her rapid heartbeat against his chest. Their sigils shone brightly underneath their clothing, a light show dancing between them with every pulse. “I… suppose you have a point. About enjoying things.” His hands left her head, sliding down to rest on her back, keeping her close as they came down.

“ **I suppose I do. You certainly enjoyed letting go for a bit.** ” She purred, forehead resting against his. “ **There’s a benefit to morbid curiosity.** ” 

Seteth closed his eyes. “So it would seem. But... S-slow.” His grip on her back tightened as he began to sort through all of the emotions shared between their bond. It was almost overwhelming. 

Saint had no problem flying them for now, but soon they would need to rest. Byleth seemed to have the same idea as she peeked over his shoulder to the saddlebags behind him. “ **You’d mentioned food? It might be a good time to stop.** ” 

The Priest, happy for the distraction, nodded. “Agreed, albeit predictable. You have a one-track mind.” An experimental kiss accompanied his tease, a gentle peck on her nose. Her brow furrowed, nostrils flaring at the gesture of affection before her smirk returned. 

“ **Two, now.** ” 

Byleth planted one last, chaste kiss on his lips before removing his hand from her back, tilting to the side to slide off of the saddle with ease. The Demon began to plummet towards the ground below, wings unfurrowing with a leathery _pop_ to catch the air. Seteth watched her for a moment, eyes lingering before directing Saint towards the ground for lunch. 

\---

They’d landed close to an abandoned farm, large fields bare and dry compared to the bustling farms they’d passed in the hours leading up. Saint was currently curled up, eyes closed while he dozed, while Seteth and Byleth leaned against the wyvern’s flank to nibble on food. Sandwiches were already devoured, drinks consumed, and now they were resting in the afternoon sun. While her chosen gazebo was her favorite nap spot, this wasn’t such a bad area to sun in either. Away from the walls, students, and worry, just out and about in a new world. 

“My hardest battle, hmm?” 

They’d set to swapping war stories, plucking grapes from a bundle. “ **Yes, I’m curious about your battle exploits.** ” 

Seteth scratched at his chin in thought. “Well, I’m sure they pale in comparison to _yours._ Goddess, another Demon swallowed you, and you fought your way out of its _stomach_? With nothing but your claws? Well, I guess that explains the smell.” Byleth lobbed a grape at his head, thudding against his temple with surprising accuracy. 

“ **If that is the reason I smell, a** **t least I have an excuse.** ” 

“Excuse me!” He narrowed his eyes, tossing a grape at her. She caught it with her mouth, settling back next to him with amusement. “...Lucky shot.” 

Her grin returned as she rested her tail on his leg. “ **Battles, please.** ” 

“Yes, yes.” The Priest thought for a moment, testing his memory for a worthy story. “There was this one time I held off an assault single-handedly by utilizing the Monastery hallway system. With the correct doors closed, you can funnel people right where you need them to go.” He spun her the tale of a raiding party in his early days of being the Archbishop’s advisor, earning the staff’s respect by routing the enemy with only a small handful of soldiers, and Saint - er, Pebbles. While Seteth spoke, Byleth ate, content. After a few moments, she turned around to face Saint, leaning to put her cheek against the beast's hide.

“It wasn’t until they saw Saint and me at the doors to the Cathedral that they set down their weapons. Their leader was the only one who didn’t balk, but I dispatched him relatively quickly.” He popped another grape into his mouth and chewed. “It is less of a… bloody victory than yours, and borders along the more strategic, but..” 

Byleth raised her hand to stop him, fingers close to his mouth as she held a grape. “ **No, it is a well-achieved victory. Not all battles are won out in an open field. It takes a tactical mind to** -” She threw the grape into the air and caught it in her mouth before returning her cheek to his shoulder. “- **route the enemy to such a state. I have seen you in battle. It is nice to know that your mental capabilities are as sharp as your spear.** ” Seteth could only grunt in acknowledgment, cheeks reddening at the praise. When was the last time someone complimented him on his work?

“I suppose I try. A sharp mind and body keep one’s loved ones alive longer.” The Demon had nothing to add, merely nodding and closing her eyes, enjoying the time in the sun with her Priest. Her wings stretched out over them - not necessarily intentional - as they soaked up the rays too. Seteth didn't mind the shade, head tilting over to rest on hers, careful of her horns. They remained like this for a while, until Byleth stirred, sniffing. 

Her nose rose to the air as she inhaled. “ **Did you bring smoked fish, too?** ” Her clawed hands lifted the lid of the empty basket, peeking inside.

Seteth shook his head. “No? I’m afraid not. I should have, though. That does sound lovely. Perhaps when we get back, which, unfortunately, should be soon...” 

The Demon’s brow furrowed as she rose to her feet, looking off into the distance. “ **Is there a town nearby?** ” 

After a few moments of consideration, given their direction and how long they flew… “Remire should not be too far from here.” Seteth should've expected a bit of resistance, after all, this was Byleth's first taste of freedom and she would have to head back to the Church so quickly. _Perhaps a few more hours - that would still give me time to process the paperwork that needs to be done, run the books, get dinner with Flayn - I did tell her I was leaving today, yes?_

“ **Ah. It’s on fire.** ” 

The implications of the sentence, due to Byleth's completely neutral delivery, didn't reach Seteth until halfway through his own vocalized thought. “It is a lovely time of year for tha- _Excuse me_?” Seteth scrambled to his feet, pulling at Byleth’s arm to get up quicker. A thick, dark plume of smoke was rising in the distance. Remire was definitely on fire. Remire Village was a simple town, but important to the Monastery and - even if it weren't - all those lives if they didn't move to help.. “Byleth - I’m sorry, we have to-” 

Her wings were already opening, the cold, calculated stare replacing the content look she had worn mere moments ago. Power ebbed off of her as she narrowed her eyes towards the smoke. “ **Let’s go. Nothing interrupts my free day and gets away with it.** ” 

**Notes for the Chapter:**

> THERE IS A SETLETH FANZINE CURRENTLY IN THEIR INTEREST CHECK - GO CHECK THEM OUT [ Setleth Fanzine ](https://twitter.com/setlethzine/status/1221195052959051777)
> 
> Thanks for the support so far <3 I'm really enjoying writing this and we're really starting to pick up speed towards the end. Enjoy the fluff!  
>    
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	13. Fight

**Summary for the Chapter:**

> Remire Village is on fire, and Byleth knows the culprit. 
> 
> She and Seteth make a decent team.

Remire village wasn’t far away on wyvern-back, even closer for the Ashen Demon. Seteth watched her fly ahead, nimbly folding her wings to dive quicker than Saint would have ever been able to. “Byleth, be careful! We don’t know what’s out there!” He yelled into the wind, but Byleth was too far ahead to hear. It was probably ill-advised to warn the Demon of War, Victory, and Blood to be ‘careful’ in the midst of a possibly inevitable fight, but the Priest couldn’t help but worry. As Byleth’s form got further and further away, he clicked his heels against the sides of the wyvern. “Faster.” The low command was lost under the thrumming wingbeats from his battle mount, huffing and growling to pick up speed.

Byleth began to circle the town, slits of her eyes thinning as she took in all of the details from the village. Humans were fighting humans, the smell and sting of woodsmoke in her nose and eyes… It was unclear from this high up who - or what - started the fiasco, but the shuffling Demonic Beasts on the grounds below reeked of the Death Knight. “ **Damnit.** ” 

“Help! Somebody, _please help!”_

The shrill cry of a child caught Byleth’s attention, almost drowned out by the ravenous, guttural snarls coming from the _afflicted_ humans. Something about them was off - again, Byleth could not tell what - but there seemed to be no reasoning with them as they closed in on cowering civilians, the child included. Everything in her body begged to fight the Demonic Beasts, tainted with the magic of the Death Knight, but it was hard not to imagine if that was how Flayn would have sounded in distress. Gritting her teeth, Byleth folded her wings and dove towards the child. 

\---

Seteth arrived at the chaos a few moments after Byleth, eyes scanning the fiery battlefield for any clues as to what was going on. 

It was proving to be rather tricky. 

Some townsfolk were fighting against one another, whereas others were simply trying to run from the beasts or their brethren, faces tear-streaked and screaming. “We must save the ones we can! Forward!” The lance in the saddle holder felt at home in his hands, despite his desperate wish to not need it. This had started as a relaxing day but was about to end with bloodshed. Part of him knew the Demon wouldn’t mind, but the other part was irate: he certainly did. Saint flew low, making it easy for Seteth to sweep up a young man off his feet, previously surrounded by feral villagers. 

The man’s shaking hands clung to Seteth’s robes for dear life as the wyvern flew. " _Oh thank the Goddess, thank you so much!_ ” 

“What is happening here?!” He all but demanded. There was no time for pleasantries, Seteth had decided, willing for answers while he tried to find a safe place to drop off the rescued villager. He spotted Byleth across the village, setting down two people near a gated building with an iron door. _Smart thinking._

Convinced he wasn’t about to be dropped into the gaping mouths of the Demonic Beasts below, the man feverishly bumbled out words. “ _We… we’re not sure. They just went mad as soon as that Demon showed up, and those beasts…_ ” The grip around the man stiffened as Seteth clenched his teeth. _Demons. Of course._ Byleth would have more insight, surely. 

Seteth’s grip loosened as he helped set the man down on solid ground with the other rescued individuals. The Ashen Demon was already breathing a bit heavily, the strain of her time magic evident - but only because Seteth had seen it before. Not daring to waste time sliding off of Saint, he cast his worried eyes to Byleth’s. She seemed at home among the carnage, but something troubled her. Something just beyond her eyes that he couldn’t quite pinpoint. “Byleth, he mentioned a Demon.” 

“ **The Death Knight. He controls the beasts. I should have known, the weak-blooded coward.** ” Her words were like ice, chilling Seteth and the survivors to the bone with their cold lack of remorse. If it weren’t for the dull glimmer of their sigils, the villagers might have mistaken Byleth for an enemy. Perhaps they did but were too afraid to move like frightened sheep, not quite lemmings yet. “ **He has been here. He** ** _is_** **here. I can smell him. The rest of them are addled in one way or another; I cannot speak to them. We must eliminate them and the beasts.** ”

He vaguely remembered Byleth mentioning tactics as a job back on her home plane, but this wasn’t the place to press for strategy. They were level-headed veterans of battle, so they would have to do with whatever they could come up with. Saint stomped a clawed foot impatiently, anxious to get into the fray, encouraged by the smoke and flames around him. Although Byleth didn’t meet his eyes, keeping her attention to the area around them for any hint of The Death Knight, she managed to rumble out a quick “ **Be careful-** ” before unfurling her wings and jumping into the pandemonium. 

\---

Claws sliced at the air beside The Ashen Demon, procuring a black, smoking rift beside her. In a swift motion, Byleth's arm disappeared inside the shadowy portal. A sword began to materialize, darkness and bone fitting together to create a jagged sword, forged in the blood, sweat, and bone of battle. It had been a fitting weapon for her fight against the beasts on her first night in the human realm, and it would be a suitable weapon now. At least now she’d be able to clamor for the satisfaction of a victory and battle against semi-worthy foes. The beasts knew better than to retreat entirely, they’d always come back. Sniveling wolves needed a meal sooner or later, whether driven by desperation or doom.

It was time to let loose. 

**“Death Knight!** ” She snarled, angrily lashing out at the first beast she saw. The sword split the beast’s thick hide, black ichor staining both the blade and the ground below as her yell was drowned out by a pained roar. “ **I know you’re here!** ” The blade was jerked to the side, creating another jagged split as the beast faltered. 

“ **Show yourself so that we can fight to true victory!** ” The sword was removed from the beast with a disgusting _squelch_ as Byleth jumped back to avoid a frenzied swipe of its massive, clawed hand. Wings unfurling, she jumped into the air to plunge her weapon through the top of its skull, a sickening crack the last sound to echo from the beast before it crumbled unceremoniously to the ground. “ ** _I_ ****_will end you, you pathetic excuse for-_** ” 

“ _Byleth_!” 

Seteth’s yell caught her attention, cutting off her sentence as she wheeled around to find him. Her ears were alert, flicking and rotating as she tried to pinpoint his location. “Byleth, someone is watching! Up near the treeline!” She couldn’t find him through the smoke and smells, already overstimulated by the battlefield chaos, but she could follow his directions. Golden and black eyes scanned the treelines, immediately spotting the Priest urging his wyvern toward an older individual, veins pulsing on a broad forehead with black eyes similar to Byleth’s. “ **Tch! Fine.** ” The Demon turned to run after them. 

Someone had to make sure Saint didn’t die.

\---

The man was malformed, be it from magic or demonic ties, but there was no denying it - this man had a contract like Seteth. No matter how grotesque or changed he was, he was human at his core. The difference between the two men rested on _why_ they had a Demon contracted and if the chaos around them was any indication of this stranger’s intention… He needed to be held accountable. The ever-deepening creases under his eyes threatened to split his head apart from sheer frustration; this wasn’t a simple mission in the slightest. It was everything he could do not to pinch the bridge of his nose out of habit.

As Seteth neared, the man’s eyes tore themselves from the carnage of Remire and focused on the approaching Priest with twisted glee. The sight made Seteth’s stomach twist with revulsion. “Ah, hello, Priest. I did not expect any of you to be out and about today. Out taking your pet for a walk?” Though it should not have been a surprise, the man’s voice was unpleasant, grating on Seteth’s nerves as he tightened the grip on his lance. 

“Spare me your taunts. Remire Village is a peaceful place, what do you have to gain destroying it from the inside out?” _What a bastard._ Seteth raised his lance, pointing the bloody tip at the assumed mastermind, unphased by the armored guards that surrounded him. They didn’t move at the threatening gesture, sitting stoic and straight as if awaiting orders. Byleth would be here any minute. If he could buy some time, they could take down the man together. 

The _sneer_ the strange man wore, the sheer _audacity_ of his apathy was the most towering testament to his character. “How unsatisfying a response. I owe you no explanation because you will not leave here alive. Dispose of him.” Dismissing Seteth with a casual gesture, a simple wave of the hand, another Demonic Beast shuffled out of the woodwork, eyes boring holes into the green-haired man. His trusted wyvern tried to backpedal, wings pumping frantically as the slavering beast picked up speed, now trotting at a torrential pace. Seteth hadn’t expected anything from the woods, but he was prepared to fight. Magic flared at his fingertips, shooting off a bright pulse of light towards the lumbering monster. 

The magic struck true, rippling across its skin, causing a massive, bloody burn. 

It continued moving.

 _Wait…_ Something was different. The beasts at Garreg Mach were quickly disposed of. Seteth had experienced no problem slaying them left and right. These monsters, for whatever reason, were stronger. The thought chilled his blood, stemming from his stomach down to his slightly trembling fingers. “Shit!” He lifted his lance as the beast’s clawed hand slammed down at Saint. Seteth was knocked off the wyvern, the wyvern sprawling off to the side with a gurgle of pain. With a metallic whir, his lance clattered to the side, just out of reach as Seteth rolled to a stop. Crazed eyes from the monster appraised the situation for only a brief moment. Orders were orders - Saint was ignored in favor of extinguishing the Priest.

Shaking hands and sore limbs grappled for purchase on the ground as Seteth scrambled to his fee, magic pulsing in both his palms. As the Demonic Beast neared, maw dripping with fetid saliva, hot breath on his face as the beast’s mouth contorted in hunger- 

Time slowed to a stop.

\---

Byleth slammed into Seteth, arms wrapping around his torso to move him before time clicked into place once again.

\---

 _Goddess!_ Time resumed but Seteth was on the ground as Byleth scrambled to action above him, elongated claws burning with the low crackle of flames. When she swiped forward, the fire startled the beast, making it clamor back in confusion. At first, Seteth was there, but now another Demon? The creature was not known for its intelligence. “ **Get up!** ” Byleth growled, tail lashing from side to side. They only had a few moments to take advantage of the stupid creature. “ **I can’t be there for you every moment in battle, you’ve faced these before.** ” 

_Do not lecture me-!_ His knee jerk reaction was bitter, but he did owe the Demon for the save. Biting back the frustration that poked at his inadequacy, he ran a hand through his hair. “Yes, but my magic isn’t piercing them as it had before. They’re empowered by something - or someone. The man with the black eye, it has to be him!” 

The Demon smirked, crossing her arms. “ **You gave him a black eye? I am impressed.** ” 

“Byleth-” Seteth hissed in frustration, pinching the bridge of his nose. “No, he - he _has_ black eyes. His eye is black already. It’s some Demonic thing - He has a contract, like me. It’s probably the Death Knight.” 

“ **Oh. That’s not nearly as entertaining.** ” The amusement on her face faltered, golden slivers of her eyes hardly noticeable in the black of her scleras. “ **Pick up your lance, then. Time to see how we fight together.** ” 

The Priest was more than happy to oblige, dashing to grab the golden lance before standing side by side with Byleth. The Demonic Beast lumbered towards them once again, this time under the watchful eye of the strange, black-eyed antagonist. His lips moved as if whispering commands into the ears of all the beasts he commanded, through the influence of the Death Knight. Between the crackle of flame and the sounds of battle, there was no way to discern what he was saying. 

The beast led with another predictable slam of its arm, looking to flatten both of them where they stood. Seteth jumped to the left while Byleth nimbly darted to the right, raking her hot claws up the arm of the beast. It recoiled with a blood-curdling hiss, free arm moving to clench at the wound she’d made. Both of the monster's arms now preoccupied with pain, Seteth slid under the belly of the beast, dragging the sharp tip of his weapon through its gnarled underbelly, already scorched by Seteth’s magic. The flesh split easily, all but downing the monster as the Priest’s pass finished. 

There was an air of superiority as the man leered down the hillside at Seteth and Byleth, unphased by The Ashen Demon’s appearance. “Adorable. Tell me, Priest, how does your _Goddess_ feel to see you fight side by side with such a creature? Do you seek her out in prayer with the same lips that summoned your monstrosity?” 

Seteth could feel the anger coming off of Byleth in waves, unsure if the own anger thrashing in his chest was from her, or himself. Still, she settled a bit when he stepped forward, brandishing the long lance in hand. “By order of Garreg Mach, I, Seteth Assal, cannot stand idly by while you insult my companion. You are free to ask the Goddess yourself after you are slain - Judgement will be passed for the sake of Remire.”

Nonplussed, the man simply watched as the guards around him turned to face their aggressors. “Laughable. You challenge Solon? I have no time to waste on the likes of you. I hold two Demons in contract, and yet you think you can kill me? Your pet is but a savage, insignificant beast-” 

“ **Watch your tongue, lest I rip it out and feed it to your corpse.** ” Byleth bristled, eyes glowing with building rage. “ **I am The Ashen Demon. Your Death Knight has fallen to my claws once before, and he will do so again. Your Plague is no better-** ” As the Demon taunted Solon, Seteth made a note of the change in expression when Byleth brought up The Plague. She’d hit a mark of some sort, though the man was careful to keep his appearances carefully even. “ **I will leave the personal bickering to you two. All I want is the Death Knight. We have unfinished business. I will claim my victory.** ”

\---

Solon was just a name. Solon was not a title, not a position. It fit in no hierarchy, so there was no reason to fear him. Humans could contract with whatever Demons they wanted - whatever fits the bill. Just because he had two meant nothing to her. He had the cowardly Death Knight that had kidnapped Flayn. That was all she needed to know. As she physically bristled, unbothered by the armored soldiers approaching, Byleth took in a deep breath, lungs filling with air. Her clawed hand grabbed at the back of Seteth’s robes and pulled him back. “Ah!”

Once it was safe to let loose, Byleth opened her mouth and roared - flames fanned from her fanged mouth, cooking the humans in their armor. When their screams died down, muffled by helmet and metal, Byleth returned her fierce gaze to Solon. “ **If I crack open that skull of yours, do more words fall out, or just hot air?** ” 

The man faltered, only slightly, as his weasely hands gripped at a shard of black glass. While Byleth didn’t recognize its use, she knew it was Demonic in nature. He whispered into the shard before aggressively raising a hand. Soldiers came from the woodwork, marching in a straight line towards Remire and the fighting duo. Additional reinforcements entered from the side, wielding bows with nocked arrows. 

Byleth sneered in return, a clawed hand on her hip.

“ **Your contingent does not scare me. I have razed armies in a single breath. My tail can level mountains, and my determination alone is enough to snuff out your pathetic existence. Give me one good reason why I** **_shouldn’t_**.” Anger bubbled in her veins, blood boiling as fury overtook her senses. An arrow whizzed towards her, but she caught it and snapped it with a tight grip. Seteth let out a grunt of surprise before it tapered off in his throat, the rise of worry instantly shattered like the arrow. He readied his lance as he and Byleth charged forward for the next wave of combat. 

\---

Byleth’s question hung in the air as Seteth followed Byleth into battle, deftly dodging weapons and punches. Where Seteth had an open spot, Byleth covered him with her tail. An arrow had been deflected off of her scales, a sharp, deadly weapon meant for his shoulder as the two traded places, claws and steel knocking together with finesse and precision. As wound up as the Demon was, as easily rattled as she could get in Seteth’s presence, she maintained a calm composure when facing down their enemies. They did work well as a team, as much as it surprised him. 

It was his turn to surprise her when a bolt of magic sent an armored assailant tumbling down the hill, knocked down mid-strike. Had Seteth not intervened, the bite of his blade would have pierced her flesh. He’d seen all of the scars on her back to know that it wouldn’t have killed her, but the thought of her getting injured to that extent was something the Priest could not stand for. Their eyes met momentarily, a nod of appreciation the only gesture shared before they returned to the carnage.

Solon watched from his perch, emotions unreadable. “Fine. You wish for a reason? The Plague, as you well know, has your Archbishop under her spell. Kill me, and both the Death Knight and The Plague disappear from this plane. The curse remains, and it will slowly kill that Demonic filth where she slumbers. Your ranks will fall to chaos, and Garreg Mach - and then all of Fodlan - will fall.” 

Seteth’s blood ran cold. How could he have known that Rhea was a Demon? It was something he hadn’t truly come to terms with himself, but hearing it from someone other than Byleth only solidified its truth: Rhea was a Demon. _Rhea_ was a _Demon._

“ **Seteth, snap out of it.** ” The Demon beside him hissed, tail thumping him on the back in an attempt to bring him back to the battle, out of his thoughts. She’d once told him that Flayn accused him of getting lost in them. He supposed they were right. “ **His words rile me up, but that makes me stronger. Do not let it do the opposite to you.** ” 

“Yes… yes. Thank you.” The grip on his lance tightened once again before he swung it in a wide arc, slicing at the exposed neck of a warrior to the side of Byleth. She’d ducked for the swing, sweeping out with a leg to knock the soldier that _thought_ Seteth would attack down on his back, surprised. His scream died out as a choking gurgle, sharp claws slicing his throat and staining her hands red with blood. Whenever one of them moved, the other had a counterattack to make up for the hole in the defense. They functioned like a well-oiled machine - Byleth didn’t have to overextend much to assist Seteth, and for as many times as Byleth saved him from an attack, Seteth managed to return the favor. They’d danced well, in more ways than one. 

Hand in hand. 

Mouth to mouth. 

Back to back. 

If Solon’s words were valid, they couldn’t kill him until they killed The Plague. Seteth knew he’d need to talk to Byleth about the implications of his statement. This entire predicament… Rhea and The Plague were two vital pieces on the jumbled chessboard they currently played on, but it was hard to focus when he and Byleth fit so well together in the heat of battle. It went without saying that she had his back.

And he had hers.

So, of course, when the mass of black magic spiked behind them, he instinctively shoved Byleth out of the way. 

\---

 _The Death Knight._

She could feel him. 

He was here. 

The remaining human soldiers were almost dispatched, the time cut in half now that she and Seteth were fighting back to back. They hadn’t suffered many wounds between the two of them, proving that Seteth was an adequate partner in the field of battle. If she needed more proof of her choice, this had been it. Though, it was a bit alarming how often she’d strayed her attention to him mid-fight, rather than forward to a new enemy. She wrote it off as keeping her contract holder safe. If something happened to him, she’d be sent back. 

The shove came as a surprise, nearly sending Byleth onto her face into the dirt as the spike in magic threw off her senses. The black magic rippled in the air as it sped towards Seteth. In her last bit of magic, pure reflex, time began to still around them until it slowed to an agonizing stop. 

_A brief respite._

The world was silent, save for Byleth’s heavy breathing and the drip of blood from her fingers to the ground below. Here in her own world, she could catch a bit of rest at the expense of her magic, and yank her idiot contract holder out of a nasty situation. She could not see the Death Knight yet, but there was no doubt who’d cast this spell. He was nearby and was trying to target them from behind. 

He never was one to try and strive for real victory. Cowardly tactics were unbefitting a Demon with ambitions such as his. To take her title would be laughable; there was no one less worthy. Perhaps she would make his reincarnation her jester when she ascended to her father’s throne. 

Solon, his contract holder, sat frozen in time atop his rock, mysterious eyes watching their fighting forms with interest. Overconfidence led him to spill his plans rather early, leaving no questions of his ambitions. At least, that’s what Byleth figured. The malformed man had no intention of letting them go alive, but Byleth had already put a plan into motion. Saint was - by her command - hiding nearby, waiting for her signal. They couldn’t have their speedy escape hindered by a tired wyvern. Besides, Seteth had a dragon beside him, whether he knew it or not. 

Seteth. 

What a fool. 

She stood and walked to his side, examining his features frozen in time. _Such focused eyes, staring down death magic in the face, hardly unflinching_. It was something to admire, in a way. Byleth couldn’t bring herself to do so, though. He’d gone and committed the worst crime of battle - making stupid mistakes for the sake of another. Be it affection or just noble stupidity, it would do neither of them any good if he were to fall here. Byleth would be sent back to the Demon plane, and he’d die, leaving Flayn alone and Rhea to slowly rot. While she didn’t care about the country itself, she’d grown accustomed to the friendlier faces around the Monastery. Even though she could count on one hand the number of people she tolerated within those walls. Loyalty was a trait she knew she had at least. Perhaps the Priest had been correct in his statement that she could be more than her core three. 

Her hand cupped his cheek, bloody hand leaving a smear where she touched, fingers trailing down his jawline before resting her forehead against his frozen chest. “ **Stupid human.** ” The edge of her vision blurred, a hint that she’d all but run out of time. Clawed hands grabbed at his robes, dragging him away from where the magic would detonate once time returned to normal. The world rippled as it attempted to right the timeline.

The spell exploded as time caught up.

\---

One moment Seteth Assal was staring down the barrel of a massive explosion of magic, and the next, he was staring at Byleth - a force that was even more terrifying, given the way she was glaring into the depths of his existence. Her eyes burned angrily, hands gripping the front of his robes as one would do to intimidate. Such a troubled expression, words hidden just out of reach. Her mouth opened to speak - chastise him - pointed canines glinting in the light to add more danger to her already pointed words.

No.

Her jaw clicked shut with an audible snap, fingers releasing the hold on his clothing. Among the adrenaline that rocketed through his body, he could almost feel a sense of relief coming from the bond. _Thank you, Byleth._

**_“I knew it. How pathetic.”_ **

A deep, jarring voice rattled the air around them, screeching against Seteth’s nerves like nails on a chalkboard. It sounded like multiple voices speaking at once, ready to drill into his skull and rattle around like loose coin. Although he was loathed to admit it, everything about the Demon before him filled Seteth with a sense of black dread, a feeling that drug him down like feet slogging through mud. While he did not recognize it, Byleth seemed to, posture hunching as if the woman were preparing to launch into a feral frenzy. Solon looked ahead, chin raised high and bold as a Demon clad in spiked armor began to materialize beside him. “Behold, my first Summon. The Death Knight.” 

Byleth’s tail lashed in a fury, knocking a helmet clear off a slain warrior’s head. It rattled down the hillside with metallic thuds until it rolled out of earshot. “ **We know who he is, you overconfident sack of sh-** ” 

“ _ **S**_ ** _ilence, Ashen Fraud._** _”_ The Death Knight’s voice commanded, holding a hand up to add insult to injury. Much in the same way Byleth had when he’d first met her, everything about this Demon commanded respect. The last thing Seteth wanted to do was give it to him, but his _presence_ almost demanded it. “ ** _You’ve been protecting this human the entire fight. Every arrow, every beast, every spell - I was correct. You’ve gone soft."_**

Seteth wasn’t sure he’d ever seen Byleth so angry and conflicted. The first few days of life at the Monastery with her were difficult, yes, but this was a new level of hate he’d yet to experience from her. Despite her rattle, her eyes never left the opposing Demon. “ **I protect him because he’s my contract holder, same as you. If something happens to him, I miss my chance to feel your bones crunch beneath me.** ” _Control yourself, Byleth. Don’t do anything rash,_ Seteth urged. “ **You know, we never got to finish our fight. Now is the perfect opportunity. Back up your master’s claim of superiority. Why don’t you whip out that** ** _scythe of yours_** **\- oh wait.”** The rumble in her chest - Seteth had heard it when she was happy, usually with him - picked up slightly. **“You left it behind as you** **_fled_ ****like the** ** _dog you are_** **.”**

Though Byleth’s defiant words brought a smile to his face, something about this exchange didn’t feel right. Byleth was content to trade conversation with the other Demon, but what did Solon have to gain out of it? Utilizing subtly, Seteth reached out with his magic, visualizing the white water splashing across the hillside, slowly pulling like an unknown tide up the hill toward Solon. It ebbed and flowed like the ocean’s waves, slow and methodical to keep under the magical radar. While he couldn’t do any physical damage, perhaps he could feel if any spells were being prepped…

The Death Knight chuckled in response, an unnatural sound. “ ** _A dog, am I? What does that make you? An eager bitch, running in circles, jumping through hoops for a master in hope for a treat? Your bond with this human makes you weak. What even are you anymore? You may fight well together, but I know what you truly are. Does he? I would love to fight you one on one. Put a General in her place. Why don’t you whip out that true form here and now?_ **” 

The magic Seteth pushed stopped momentarily, confused at their conversation. True form? Byleth was a Demon that utilized magic, sure, and he’d seen her change different parts of her body for more deadly applications, like claws and fangs. But that was what she was. 

_Damnit, Seteth, don’t get distracted!_ He focused on the silent spell once more, trying to keep his expressions to a minimum. The last thing he wanted to do was give the opposing Demon anything to work with. While the question the Death Knight had posed made Seteth think, he wondered how Byleth would answer. She took her time, the tip of her draconic tail flicking methodically.

Wait. This was something to make her think, not attack. That was it!

The moment his magic reached Solon, sneaking waters taking him by surprise like a high tide, Seteth could feel the teleportation spell their enemies had been prepping almost reach completion. 

“Byleth! They’re trying to teleport away!” 

\---

_Your bond with this human makes you weak._

_Your bond with this human makes you weak._

_Your bond with this human makes you weak._

_Fuck!_ Byleth could feel her skin chill, gooseflesh rippling up every inch of her skin.

_There was a mirror, as tall as the eye could see…_

_No!_ There were too many unknown factors; she couldn't bring herself to look at the reflection.

She couldn’t transform. Not here. It would take too much time, and time wasn’t something they had enough of. What would Seteth think? 

Wait.

No. Fuck what Seteth thought. It was what she was. Blood and death and power incarnate. He would see her and be in awe at what she could honestly do. What she truly was. 

“Byleth! They’re trying to teleport away!” 

_The glass breaks, shattering into a thousand pieces._

_Shit._

The Death Knight rumbled, almost impressed. Unlike her purring sound, it was a grate, like metal against stone. “ _ **V**_ ** _ery astute, Priest. Too bad it is too late.”_ **

Solon grinned from beside the Demon, a grotesque grimace with missing teeth. “Yes, too late indeed. With the Demonic Beasts and The Plague’s sickness, your precious Archbishop is doomed.” The spell that had been dancing between Solon’s fingertips quickly engulfed the pair, their features slowly fading from view. “Take care in knowing you saved a village of unimportant souls when all of Fodlan was at stake.” 

“ **No! Fuck!** ” The Ashen Demon snarled, wings opening as she jumped to stop them, bloodied hands outstretched in a desperate attempt to grab hold of _something. Anything._ Her claw brushed against the armor of the Death Knight at the last moment before the two faded entirely from sight, leaving nothing for Byleth to tumble into. The angry Demon zipped past the spot they’d been standing, crashing into the treeline behind the rock Solon had tormented them from. 

_That… could have gone better. It could have gone worse - but it could have gone better._

The immediate danger was gone for now, but Seteth didn’t allow himself to relax just yet. “Byleth!” His feet jumped over bodies they’d dispatched, running towards the woods he’d seen her disappear into. So many dangers had breached the woodline during the battle, but if they were lucky, nothing else was hiding. When Byleth’s head poked out from the dense undergrowth and not another Demonic Beast (Byleth didn’t count), he let out a sigh of relief. “Byleth, are you oka-” 

“ **Yes, I’m fine.** ” By the way her jaw was set, and how her teeth clenched, he could tell it was a lie. She shouldered past him, back to the rock they’d disappeared from. She dropped to her knees and sniffed at the surface, picking up their scents in an attempt to refresh them. Commit them to memory. “ **Damnit, damnit,** ** _damnit_** **.”**

 **“** Byleth, it’s… it’s okay. We know their plan, and we can prepare. I’ve heard his name before. I’m sure with a little research and preparation, we can work through this. The speed of the battle did not leave us room for tactics, but if we are given time to prepare a strategy, I am sure that we will bring them to justice with ease.” It was no secret that the Ashen Demon was a sore loser, but he honestly felt as though she had no reason to feel like this was a loss. Given how she glared down at razed Remire, he knew she was feeling it. “Here, let’s find Saint and get back. We need to get help for the Village.” 

\---

Seteth offered Byleth his hand, attempting to help her up off of the ground. Her claws were threatening to scratch divots into the stone itself, not unlike what he’d seen in the underground chamber below the Monastery. The thought gave him pause, but he didn’t move his hand. A quick swipe of her tail batted it away, the Demon struggling to her feet with fatigue. The slits in her eyes were still thin and sharp, angry with the world around her. 

And him. 

After wheeling around to face him, she pushed at his chest, ears folded back in frustration. “ **You were an idiot. Never sacrifice yourself for another on the battlefield. You could have** ** _died!_ ** **What would you have done if I couldn’t have stopped time? What of Flayn? What of this whole** ** _plan_** **they have?** ” Her arm gestured beside her, where Solon and the Death Knight once stood. “ **I got a battle, but at what expense? I’ve seen it time and time again - Stupid mistakes. I thought you were better than that.** ” Her emotions were all over the place, thrumming through the bond like the strings of a guitar. The sound wasn’t unpleasant, riddled with anxiety and worry - all hint of the prior bloodlust gone. She was coming down off of the adrenaline, and Seteth didn’t blame her.

She truly was a beast of war — a beautiful force to be reckoned with. 

Convinced she was finished, Seteth reached for her hands to pull them close. He ignored blood that caked them, pulling her into a hug instead. “I’m glad you’re safe, too.” The Demon didn’t have the words or way to express how she felt, but he’d spent enough time with her to tell. 

There was a soft rumble from her chest, not quite a purr. It reminded Seteth of the ‘conversations’ she’d had with Saint and as if on cue, the wyvern’s silhouette could be seen flying against an early evening sky. Byleth didn’t say another word - at least, not in English - as Seteth tightened his grip. 

\---

Saint would not be able to carry all of the survivors, but Seteth had promised to inform the Knights of Garreg Mach of the events so that the wyvern and pegasus riders could dispatch immediately. They were wary of Byleth, who kept off to the side, but thanked Seteth profusely for the assistance. Thanks to their combined efforts, only one civilian fell in the attack, and several buildings were salvaged. There would be much to do to make Remire a safe village once again, but the surviving villagers were hopeful. It was that hope that Seteth prayed would launch them into a new era of prosperity. 

When the diplomacy was out of the way, Seteth returned to Byleth and Saint, ready to begin the trip back. Their wounds were superficial, but it was no secret that Byleth was exhausted. She was quiet and muted, eyes half-closed when she didn’t need to be paying attention. The way she kept her back to Saint confirmed it, too tired to keep total watch around her.

“Byleth, will you be okay to fly?” 

Seteth was already prepped on Saint’s back, turning the wyvern around in the direction of Garreg Mach. The Demon slowly nodded, wings unfurling slowly. There was no showy _pop_ or loud snap of her leathery skin pulling. She was simply existing, and Seteth wanted nothing more than to be able to carry her back himself. Still, she was stubborn and insisted. The quicker they got back to the Monastery, the faster she could get rest. 

They both could use it. “Away. Let’s go home.” 

The wyverns took to the skies.

\---

Every wingbeat threatened to slide Byleth into a drained sleep. Even now, with what felt like the halfway point back to the Monastery, she was struggling. Seteth had tried to keep her entertained with talk of battles or of Flayn, but nothing seemed to hold her attention for long. Often she would slow down, and Saint would rumble to wake her back up.

When a wingbeat faltered, and the Demon lost a bit of altitude, Byleth snapped back to reality. Night had already fallen, the skies dark and quiet. How much time had passed? The lack of light hid Byleth’s darkening cheeks, embarrassed at her fatigue. The wyvern under Seteth growled with irritation. Once again, another conversation was struck up between the two, and while the Priest had no idea what was being said, it seemed as though Byleth was on the receiving end of a rather heated castigation. Thoroughly chastised, the Ashen Demon banked to the right to get closer to Seteth. “ **He is commanding that he fly us the rest of the way. He insists that since he did not fight, he is strong enough. Do you mind if I slide behind you?** ” 

Seteth’s hips rocked forward in response, sliding a bit to make room on the rest of the saddle. The aerial acrobatics were not complicated, especially with the promise of a bit of rest, so Byleth mustered up the rest of her strength to nestle onto the wyvern behind him. Once safely seated, her wings fell slack against her back, heavy like weights and utterly exhausted as the rest of her body. As much as she tried to stay awake, the moment her forehead leaned against Seteth’s back, sleep took her.

\---

“Byleth.” 

...

“Byleth, we’re about to arrive at the Monastery.” 

Seteth’s gentle voice interrupted her short nap, rousing her from much-needed slumber. Her body ached for more, but that had to come later. Unfortunate. The tired Demon sat up and opened her wings, thankful for the few hours she was able to steal. The appendages caught wind, and she lifted off of Saint with ease, moving to fly alongside Seteth once again. “ **Thank you.** ” She really was tired. There was no teasing, no joke. Innuendo took too much effort: just gratitude and silent yearning for sleep. 

Stopping time must take more from her than he realized. He made a mental note to not rely on it further. “You are welcome. Go clean up and get some rest. I will inform the Knights, submit a report, and then do the same.” 

All Byleth could do was nod. 

When they landed in the courtyard hours later than anticipated, the Knights were there to meet them. Flayn waited anxiously, immediately started by the blood and cuts that were visible on her father. “ _Goddess_ …” The child shouldered her way through the contingent of warriors, running over to Saint’s side as Seteth slid off. Byleth landed a few paces off to the side, wings folding lest they dragged behind her.

“Oh, I was so worried! You said you’d be back by dinner, and when it came and went - Oh, we just knew something was wrong!” Flayn’s tiny hands gripped at Seteth’s. For once, Byleth was happy the blood from the battle had been wiped away. Such pure palms didn’t need the stain of war on them. 

The doting father crouched, despite the soreness in his muscles post-battle, and kissed her cheek. “I’m sorry for worrying you, Flayn. We are fine. Forgive me for missing dinner - I’ll make it up to you tomorrow. Unfortunately, I need to go file a report on what _did_ happen.” With one final parting kiss, this time on her forehead, he stood and walked off with Saint toward the stables, Saint in tow. The Knights followed, immediately alive with overlapping, intense questions. 

Flayn’s eyes turned to Byleth as she quietly walked over, noticing all of the blood and gore that stood out against her gray skin. “A-Are you okay, Byleth?” 

She did not crouch to speak to Flayn, instead electing to walk towards their rooms. “ **I am fine, little minnow. Most of it is not mine.** ” Byleth added with a wink. “ **I suppose your father and I can tell you about it tomorrow. I should probably clean up before the students think I’m the one that beat him up.** ” 

“Oh! _Oh no!_ That would be awful! I cannot imagine you two fighting.” _Oh, the irony._ The child accompanied her until they reached Seteth’s chambers, thankfully astute enough to pick up on Byleth’s complete and utter _exhaustion_. She was sure to be questioned tomorrow, but that was a problem for tomorrow-Byleth. Today, no, tonight-Byleth only worried about how warm a bath she could sink into, and how quickly she could fall asleep. Seteth would come in eventually if the knights were as considerate as Flayn. 

The Demon wasted no time stripping herself of the bloodied clothing, tossing it into a corner. As she sunk into the warm water to wash away the filth from battle, the sigil on her chest glimmered. A battle was had - another stipulation achieved. 

\---

As exhausted as Byleth was, it was hard to sleep without Seteth nearby. There was no point in falling asleep when he would enter the room at any moment, draw a bath, and then make noise until he fell asleep as well. Instead, she took to leaning her head back against the edge of the bed in quiet contemplation, running the events of the day through her head over and over. It had been an enjoyable flight, and she even enjoyed the battle if her sigil was any proof, but there were too many layers to the mystery surrounding Solon. How did he know that Rhea was a Demon? Did he know what Demon she was? How did he get The Plague to cast a sickness on her? So many questions, so little time. For a Demon that could manipulate it, it was a shame that it couldn’t solve all of her problems. 

A lock clicked at the entryway to the chamber. Seteth entered through the dense, wooden door, closing it behind him as quietly as possible. It wasn’t until he saw the edge of Byleth’s horns poking up over the side of the mattress that he realized she was somehow still awake. Although sleep threatened to claim him at any moment, he veered away from the washroom to walk to the other side of the bed, tired eyes regarding his roommate with confusion. “I thought you would be asleep.” 

Sleepy Demon eyes blinked lazily in return. “ **I was waiting for you. Figured you could use conscious company.** ”

Seteth laughed, running a hand through his dirty hair. “I do not know how much company I will be. I do not plan on remaining conscious for long. After I clean up, I intend to go straight to bed.” 

“ **As is mine.** ” 

The Priest left it at that, a small smile tugging at the ends of his mouth as he slipped into the washroom to clean up. Sleep teased Byleth, the nest looking more and more inviting as time progressed. Soon the siren call was too much to bear. When Seteth returned from the washroom, Byleth was curled up, eyes watching him as he settled under the covers. “ **We have a lot to talk about. Not now, of course. I wish to be anything but awake at the moment. But tomorrow.** ”

Seteth folded his glasses and set them on the nightstand on the far side of the bed where he used to sleep. “I agree. Tomorrow.” 

Byleth cleared her throat. “ **Thank you for having my back today. It was nice to fight alongside an equal**.” Sleep slurred the occasional word, but it was that level of earnest that made Seteth believe it.

The covers were cold, unwarmed from lack of body heat. Seteth aimed to remedy that as he pulled them closer around himself. “You are certainly welcome. Thank you, as well. If it weren’t for you, I might not be here. I would not have lived to return to Flayn, or have been here to help get assistance to the survivors of Remire.” While it was their joint idea to go flying in the first place, Seteth could not place the blame of his battle actions on their foray out together. Despite the way it had ended, it had been enjoyable. Enlightening. Invigorating. 

It _technically_ wasn’t over. “Did you enjoy the day, at least? I am sorry we could not schedule it sooner. I will do my best in the future to-” In the future? How much of a future were they guaranteed? It was a bit too early to think about future exploits. “-get you out of the Monastery more.” 

The rumbling purr he’d grown so fond of returned, slowly humming to life. “ **I would like that.** ” 

Her eyes were closed now, breathing slowly as sleep neared. Seteth debated for a moment, engaging in mental acrobatics that made his head spin. _The day isn’t over yet._

“B-Byleth.” 

“ **Hrm?** ” He could _just_ make out her shining eyes in the low light. His heart pounded in his ears as he worked up the nerve to speak once again. 

“I would like it if you joined me. If you wish, of course.” Silence. He didn’t hear her stir. _Damnit, Assal._ “But please do not feel obligated or pressured in the slightest-”

Byleth rose to her feet quietly, standing beside the bed for a few heartbeats. He couldn’t hear the footsteps of the predator he’d just invited to share his bed, but suddenly she was there. He couldn’t even tell she’d slipped under the covers until he felt her press up against his back, wrapping an arm over his side and a leg in between his. There was no sensuality, no teasing, no dragging of claw tips up his side to set his skin aflame. The tuft of fur at the end of her tail tickled the skin of his calf as she wrapped it around one of his ankles in the strangest gesture of intimacy he’d ever experienced.  
  
This position was probably easiest for her, given her horns. “ **... got your back.** ” She murmured sleepily. He was astounded she was still awake enough to speak but was even more astounded at the simplicity and affection of the gesture. 

“Yes, you do. Thank you.” The Priest couldn't help but smile.

“ **Mhm. ‘welcome.** ” There was a bit of shuffling behind him as she nestled closer, nose in his hair, close to his ear. Her breaths were steady and even. Slow and comfortable. 

“Goodnight, Byleth.” His fingers reached up to interlock with hers. It was highly likely that the moment he fell asleep, their fingers would slip, but until then, the feeling was worth it.

“ **...g' night...** ” 

Seteth had never slept better.

**Notes for the Chapter:**

> THERE IS A SETLETH FANZINE CURRENTLY IN THEIR INTEREST CHECK - GO CHECK THEM OUT [ Setleth Fanzine ](https://twitter.com/setlethzine/status/1221195052959051777)
> 
> *revs engine* 
> 
> Buckle up kids. Ashes goes from 0 - 100 now.  
>    
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	14. Journals

**Summary for the Chapter:**

> A collection of journal entries before the march to Gronder Field.

**Wyvern Moon**

**10-5**

_It's been a few days since Remire. Spies have been dispatched to find Identity of Solon. I spoke with Anna - she is always good at finding the right people with loose lips. Hoping to find out information as well as home base for Solon to attack. The knights are already spread too thin: need to find students that are capable to help bolster ranks._

_I feel sick thinking about it. Must think of a way to avoid this. Cannot lose more people on the battlefield, especially the children._

_The utilization of Byleth will be paramount._

_Byleth had trout for the first time today. Somehow achieved a Significant Victory stipulation. I am not complaining._

_\---_

**Wyvern Moon**

**10-6**

_Assisted Byleth with an assessment of the students, and have formed a team of advanced students to work under Byleth. It is my intention to keep them as a unit in the upcoming fight against Solon but needed Byleth to help choose them since she will be fighting alongside. With her time abilities and masterful tactician work, I believe they are in excellent hands for the unfortunate task of the Monastery’s dirty work._

_I hope this helps alleviate the pit in my stomach. If we are truly stretched so thin that students must assist, then I am glad they are under her protection. If it comes to battle, it will be easier to focus on the task at hand. To help Byleth focus, I have given her a journal and suggest that she write in it as often as she likes, to assist with organizing her thoughts with the students._

_This has been amusing thus far, a drop of mirth in the sea of unease._

**Wyvern moon**

**10-6**

**Seteth is making me write about shit.**

**I have to work with students.**

**They're okay. I like Felix and Claude. The rest are... okay.**

**This is stupid.**

**\---**

**Wyvern Moon**

**10-7**

**I caught a fish and gave it to Flayn**

\---

**Wyvern Moon**

**10-10**

_Went to the infirmary for a slight cough. Manuela could not figure out what ailed me, cited smoke from Remire could have aggravated lungs. Was given something to drink to assist with my throat and returned to work. Manuela must have said something, because Byleth immediately began piling blankets on me once I returned to my chambers. After swearing that I was not sick, she released me from the mountain of warmth._

_While she cited that it was merely to put a barrier between us, and help not get her sick, the gesture did not go unnoticed. She is becoming rather palatable._

**Wyvern moon**

**10-10**

**Seteth coughed a few times, once on me**

**If I get sick I'm gonna smother him in his sleep**

**\---**

**Wyvern Moon**

**10-14**

**Looking forward to sleeping in.**

**\---**

**Wyvern Moon**

**10-15**

_The Eastern Wall was completed, I was not aware it was almost finished. The moment the final stone was placed, Byleth awoke with a shriek, immediately slipping out of the window in the early morning to fly outside of the walls. When I ran outside and found her outside the gates, she looked as though she’d been burned all over. I am getting distracted by all of the work. Goddess help me stay on track._

_After healing Byleth, I found a small spot in the wall that I could break. It is a small chunk of stone that broke the perimeter, allowing Byleth to enter again. I’ve covered up the spot with magic so that it isn’t visible so that the grounds men do not plug it up. The chunk is in my office. Consoled the dejected Demon, did not get much work done today._

_Note: Byleth got meat stipulation today - I made sure to get her something nice in exchange for her being woken up in agonizing pain. I still feel guilty for forgetting. Flayn stopped by with chocolate. It was a lovely evening._

**Wyvern Moon**

**10-15**

**I did not get to sleep in today**

**Flayn brought chocolate**

\---

**Wyvern Moon**

**10-22**

_Garreg Mach received distress call from neighboring village - More experimentation via Solon. Byleth and student team dispatched: no casualties, students remark that Byleth was an excellent tactician and kept them safe. Claude expressed distaste- Byleth stopped time to yell at him for missing an easy shot. Students claim she is a difficult leader, but that they have never progressed so quickly._

_Will speak to Byleth about “constructive criticism”_

_Note: Byleth completed the battle stipulation._

**Wyvern Moon**

**10-22**

**Took students out to another village. Caspar is good with his fists. Mercedes healed a wound that Felix got, but he would've gotten more if he hadn't implicated wearing sheaths at his side. He has adopted a similar defense style that I use with my tail. He is pretty resourceful. That being said, I was impressed with the confidence and bold moves from Sylvain. Seteth himself will not be able to hold me back if he asks me any question regarding my horns and ‘handlebars’ ever again. Dimitri was useful subduing him before I did.**

**Caspar: always leads with right, needs to work on footing**

**Sylvain: overextends often, needs to work on juggling immediate and distant attention**

**Dimitri: Too easily distracted. Unsure if hesitancy or overeager reaction to blood - possible liability, will watch his progress**

**Claude: Accuracy in smoke leaves much to be desired. Will go over fog/low visibility training.**

**Mercedes: Did an amazing job. Is precious. Can do no wrong.**

**Felix: Defense improved from utilizing sheaths, does not fight as a unit however. Will pair him up with Dimitri to give him someone to look after - hopefully give Dimitri something to focus on outside of blood**

**Seteth: Very strong fighter, hard body for physical maneuvers, capable of hitching a target over shoulder with a spear with upper body strength. Lack of upper body mobility on wyvern back, but Saint and Seteth make a good team. When fighting alongside myself, easy to cover up his weak spots (always leads with right foot, right handed, on attack leads with his spear always steps forward with right foot, double armed opponent could take advantage and injure leg or foot. Good reach, good battle awareness. Could benefit from partner fighting frequently, multiple bodies makes it easier to make up for a two handed weapon weakness.**

**I have many more thoughts on the subject, but I am tired - I am also not sure why I am explaining this to the paper. Humans and their customs are strange.**

\---

**Wyvern Moon**

**10-24**

**Seteth said we will be going flying in two days. I am excited. It is for work, but we are going alone and I cannot stop the rumble in my chest.**

**Seteth has not coughed recently. I escaped the ‘sickness’ unscathed.**

_\---_

**Wyvern Moon**

**10-26**

_Took Byleth flying. Outside reconnaissance on different villages. Picnic ensued. Hard to enjoy self when the pressure of Solon hangs over our heads, but it was nice to get out of the Monastery._

~~_Byleth makes me feel s_ ~~

~~_Byleth makes me feel li_ ~~

_I struggle with the thought that once Rhea is saved, she will be gone, but I cannot dwell on this fact for too long. There is too much at stake. I must make sure the Monastery is safe for Flayn._

_I feel as though I am being pulled in too many directions. At least Byleth listens when I need to express my frustrations._

**** **Wyvern Moon**

**10-26**

**Flew with Seteth. Had a good time.**

_\---_

**Red Wolf Moon**

**11-2**

_Spies returned with information - Solon was an old employee at the Monastery - Quit a few years before I left, spouting nonsense about Demons in the church. How little the records know, what would they say if they knew he was correct? I have no way of knowing what would have happened if Solon had retaliated while still on Monastery grounds. Would Rhea have silenced him? I wish I could speak with her._

**Red Wolf Moon**

**11-2**

**Spies came back and know who Solon is. Fuck that guy. Fuck the death knight. I swear I'll eat him**

**\---**

**Red Wolf Moon**

**11-5**

_Anna returned from scouting: Gronder Field is experiencing a strange phenomenon, and the rumble of distant beasts worry the surrounding towns. It is likely that Solon is near here. Because of this, we’ve settled to leave in a week’s time. The path to Gronder is straightforward, but we will take a path less travelled to avoid suspicion or to avoid alerting Solon._

_I have alerted the student team, as well as Byleth. The knights are ready to move out. I am putting Catherine and Shamir with the student team because I can trust them. Byleth is less than thrilled, but she was soothed when I mentioned it would make me feel better._

_Things have been well between us, as of late._

**Red Wolf Moon**

**11-5**

**We know where Solon is.**

**Gonna eat death knight**

_\---_

**Red Wolf Moon**

**11-6**

**Seteth has informed me that I cannot eat the death knight by myself, and that we will be leaving in a week or so.**

\---

**Red Wolf Moon**

**11-10**

_We leave for Gronder in two days. Byleth is antsy, but we will clash with Solon before the end of the month. I hate to leave Flayn, but I would never bring her with us. I’m leaving her with Manuela and Hanneman, as loathe as I am to trust her in the hands of anyone outside of myself. Or Byleth._

_I have a few concerns, but I believe that we will emerge victorious._

_\---_

**Red Wolf Moon**

**11-11**

(The page is spotted with the occasional drop of water. A few spots are smeared from apparent water damage)

_We march tomorrow, everything is prepared. There is nothing more I can do but hope that everything goes to plan._

_In the event that we do not return, I hope that this journal entry makes its way to Flayn._

_Flayn, dearest. I love you with everything that I am. I am horrendously, horrendously sorry to leave you in such a manner, but know that everything I did was to protect our home at the Monastery. Know that I - and your mother - loved you dearly. It will be my greatest regret to not be able to see the lovely woman and the strong, stubborn intellectual you will become. I love you, I love you, I love you._

_I hope you will never have to read this, and that these are the paranoid words of an overprotective, overburdened man._

**Red Wolf Moon**

**11-11**

**I have decided that this process is dumb, and that these things should only be used to document victories. I’ll leave my dumb book with Seteth’s and when I return I will fill it full of the victories I have from the battle to come. The Death Knight and Solon are wrong - I am not a pet, and I am not weak**

**My next entry will be an ultimate victory.**

**I am coming for you, Death Knight.**

**Notes for the Chapter:**

> Oh my goodness. 
> 
> I’m so -so- sorry for the wait on Ashes. I work in the medical field, and am considered a front-line fighter in healthcare against COVID-19. I’m working a LOT and have been shipped up to Boston to try and help with the hospitals up here for the next three months, but unfortunately it eats up a lot of my time. I’m seeing a lot of stuff at work too, so it’s making writing difficult. People are definitely dying and it’s important that you all stay safe.
> 
> I have a bigger chapter I’m working on, but I wanted to throw SOMETHING out, I feel so so bad it’s taken so long to update but this virus is rough. I’ve gotten about half of Gronder written, but I haven’t gotten any quarantine time - it’s been 0-100 as soon as this started. I promise I haven’t forgotten about Ashes, or fic writing in general. I am widdling away at commissions as well, and Zine pieces, but my first love will always be Ashes and I will absolutely see it to completion. I just wanted to give something to help tide over, even if it isn’t much. I’m really sorry <3 Please stay safe, and give some support to your local hospital staff. We’re going through a lot right now. 
> 
> <3 Tyger
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	15. Fall

**Summary for the Chapter:**

> The long-anticipated battlefield. Gronder.

“Byleth, if you would just _listen_ for a moment-” Seteth’s gritted teeth betrayed his frustrations as he paced around the watch post, addressing the only soul awake at such an early hour. She remained silent for a moment as she kept sentry. Nothing would get past Byleth’s sharp vision, enhanced at night with the pinpoint pupils of a demonic entity created for the hunt, and she was putting that to the test rather than face the irate Priest before her. There was a palpable tension, uncomfortable at its root, but the crackle of the fire helped add the ambient noise that filled in the space Seteth’s words didn’t. At least, not yet.

“ **I am listening.”** Deadpan as ever, Byleth scanned the horizon. Before her lay Gronder field, a large expanse that would be their battlefield. Between spy imps sent to watch them by Solon (adequately dispatched by Seteth's attack demon) and the telltale signs of demonic activity skyrocketing as they approached the area, a battle was imminent. The contingent was sleeping before the battle, anxious and ready for first light and first blows.

Seteth’s fingers pinched at the bridge of his nose, glasses removed for better effect. “Byleth, I do not understand why you felt the need to snap at the knights today. Tensions are high as is, and it is not doing you or them any favors to cause unrest. I thought we agreed that you were going to try and-” 

“ **Try and what, Seteth? Behave?”** The Ashen Demon growled. “ **I am born of blood, ash, and victory. I am not here to make friends. I am here to fix your precious priestess and to help you dispatch of a few other demons. People have forgotten what I am. Perhaps this was to remind them.”** Her aggression was misplaced - Seteth had not done anything wrong. It took everything in her power to not be angry at the reverberating words that bounced around in her skull. Every time she closed her eyes, she heard The Death Knight mocking her. Calling her soft. Weak. She’d done everything right for Seteth thus far, but the attempts had gone unnoticed to another of her kind. Byleth had been told there was strength in bonds, but what was the point if it wasn’t visible? She did not technically _feel_ more substantial. They gave her something to fight for, but was that it? It wasn’t palpable or visible, unlike this tension and frustration. 

Seteth was undeserving of it, but he would have to take it. At least Byleth could acknowledge that. At least he was sturdy. She expected a retort, but what she got was something different. When she managed to tear her eyes away from the horizon, his eyes were boring into hers. “What are you then?”

It should have been an easy question. Of course, she knew what she was. Byleth opened her mouth, ready to give him an answer as if he were a youngling - a patronizing, ridiculously over-sarcastic response was prepped and ready for deployment. And yet. When she looked into the mirror in her dreams… It was always different. Tonight would be no different. What would stare back at her amidst the flames of war?

She closed her mouth, teeth clicking as she set her jaw. Seteth took her stalled silence as an opportunity to continue. “I do not think there is a singular individual who has forgotten that you are a demon, Byleth. We are all aware of your immense power and capability-”

“ **Hardly.”**

“ _However_ , there is a time and place to show it. Please, in the future, take your frustrations out on Solon and the Death Knight, and the Plague. Not our allies.” 

“ **I have no allies.”**

There was a pause as Seteth raised an eyebrow challengingly. She said something wrong.

“What am I, then, Ashen Demon?”

 _Fuck._ Byleth gritted her teeth in return, turning her head away to look at another portion of the treeline. There was no mistaking it however - his eyes were still locked on her. There was something about hearing _that_ come out of his mouth, being addressed so _formally_ that made her skin prickle. The hair on her neck rose, and she had to bite back the irritation that had already been simmering throughout the day. “ **Hush. You know what I meant.”**

\----

Insufferable. The creature before him was insufferable. The importance of camaraderie, connection… humans thrived off of it, considering it an absolute necessity while Byleth treated it with vapid disregard. Perhaps it was merely a question of whether one could fight against the throes of one’s nature, born into demonic disinterest, but Byleth had been doing so well. Socializing with the students and managing to have an occasional pleasant conversation with someone other than himself. He knew how interesting and enjoyable it could be to interact with Byleth, but no one else in the contingent did. All they knew is that they were fighting to save Rhea’s life, and they were doing so against demons. All while fighting alongside one. 

One they didn’t understand. 

One that didn’t _try_ to understand. 

Even now, as she looked away to try and deflect some of Seteth’s frustration, he knew she wasn’t truly listening. All those heightened senses, and yet… He opened his mouth to speak, and her ear twitched, rotating ever so slightly to catch his words. 

Okay, perhaps he was wrong, but still.

“No, Demon, perhaps I don’t. You want to be treated like what you are?”

“ **Wait-”**

“I can accommodate it.”

“ **Seteth, wait-”**

“I am listening.” The words made her recoil, returned to her in the same deadpan that she’d given him earlier. Pettiness did not fit Seteth well, but perhaps it was the treatment that Byleth needed to recognize that her actions had emotional consequences. A fallout of lack of social interaction, no doubt, but still. 

Byleth cleared her throat and turned her gaze away from the watch to face him again. The way her ear twitched once again, and how she shifted her weight… she seemed uncomfortable. Vulnerable, in the same sense as when she’d been healed. Baring herself, but in a different way. “ **I do not know what you are to me yet. I do not think you know what I am to you either, so I think it’s still fair. Even. Your texts say eyes for eyes, yes?”** She managed gruffly, trailing off when she wasn’t sure. 

He was following well enough. “ **I do not know what you are. But you are at least an ally. This is all still new, and these are difficult ideals and feelings to follow. My aggression is undeserved among the group; you are correct. I acknowledge this. I do not apologize, but I acknowledge it. It is… hard.”** The Ashen Demon paused, scratching at the back of her neck with sharp claws. Her weight shifted again as her gaze lowered. “ **Hard to be seen as weak, hard to be told I am weak when I am not. My… my kind does not recognize me, and that is disheartening. Frustrating. Infuriating. I am told one thing is strength, but I am taught another. I wish to burn everything in sight to prove them wrong. But I do not. Burning is for tomorrow.”**

The act of sharing thoughts was not technically _foreign_ to the demon, but definitely ill practiced. Still, she continued. 

“ **I want to be stronger. I am getting my stipulations, and yet I am still unsatisfied. I have never experienced that. There is a pit I am trying to fill with the common remedies, but something is missing, and I will continue to scramble until that something is found. In the meantime, perhaps I will do better to mind my temper around those who may not understand my frustrations.”** Seteth had to admit, that was probably as close to an apology as he would get from her on the matter. A loose promise to try and avoid the situation further was more than the Priest expected, but he would undoubtedly take it. It was essential to acknowledge how she felt and how hard it was for her to have a conversation like this. It was less important to acknowledge the swelling pride he felt and the rising content that Byleth shared her thoughts and feelings with him. 

Not important. _Focus, Assal. “_ No one, including myself, thinks any less of you for acknowledging the difficulty in traversing emotional affairs. You are in the wrong, and they are owed an apology, but I cannot force you. I can, however, assist you in navigating these emotions and hopefully help you achieve a new balance. Everyone deserves to have their, er, pits stocked with the things that make them happy.” A bit rudimentary in practice, but he understood the analogy well enough. 

“ **Seteth.”**

He looked at the camp behind him, hearing the stirrings within. The next watch would take over soon. They’d have a few hours to sleep, hopefully. “Yes?”  
  
A firm, clawed hand grabbed at the front of his robe. Pulled from his musings both literally and figuratively, Seteth found himself facing the Ashen Demon in immediate proximity. Her lips were on his in an instant, rough and passionate. Like a tsunami of emotion, Seteth struggled to breathe as he floundered between the waves of her presence. She had this… power over him that he knew had nothing to do with their bond or her race. He raised a hand to cup her cheek, but before his skin could reach hers, she pulled away. 

“ **More than an ally, at least.”**

Her clawed hand released him, and Seteth quickly smoothed out the front of his robes if only for appearance’s sake. The demon stalked off, ready to switch off with the watch that was bound to arrive at any moment. Much like a hurricane, she left destruction in her wake, followed by the calming seas and slowing breezes. 

The devout Priest still had much to think about as he tried to collect himself. There were reports to be made, and he at least had to _appear_ in order.

\----

The damnable mirror. The distaste Byleth felt upon seeing the mirror on a nightly basis was only matched by the bile that rose in her stomach when she awoke. Every night was the same - something that made her skin crawl. Why couldn’t she just see what she was? Who she was? It was a mirror - it should only reflect her. And yet here she stood, shaking like a mewling hatchling, waiting for the rippling surface to reveal it’s unnerving images for her to stew on through the day. Her tail lashed, kicking up grass and scattered armor with every thrash. 

For a moment, nothing appeared. Her silent pleas had been answered, and all she saw was herself as she knew. The complacent look she'd grown to expect. Horns, tail, gray skin… It was comfortable. It did not challenge her thoughts and expectations for the world. It almost felt like home.

It did not last. 

Her reflection began to transform, hunched over like a malformed creature as her skin stretched and wrenched. Body parts cracked, bones popping and creaking as they were forced against their will. The transition was quick - painful. All Byleth could do was look on in distaste as the misshapen demon glared back at her. Gangly limbs and long tail, this Byleth was grotesque and half-formed. Dragon fangs jutted out from her lower jaw, tightening whenever the true Byleth gritted her teeth. Scarred underbite and all, the creature was the least recognizable out of all the horrors of the mirror. How could this pathetic excuse for a transformation be her?

It was laughable. 

As she laughed, the creature did as well. 

Until it didn’t. 

The reflection moved on its own, thrashing its body before dropping to all fours. Without fully formed wings, all it could do was fall into a chaotic run as it sped towards Byleth and the surface of the mirror. 

Surely it couldn’t reach?

This was merely a dream. No harm could come to her here. The only dangerous thing in the vicinity was herself - she would not be scared like some helpless whelp. 

That didn’t stop her skin from crawling as the grotesque visage lumbered closer and closer, footfalls heavy as its claws displaced the bloodied dirt and grass beneath its growing hands. As it neared the mirror, Byleth could feel the glass begin to break as the sheer force of the beast shattered the dreamscape, rocketing her awake as the scattered glass slowly faded from her mind. It took a moment for her thoughts to collect, the bright glints of the creature’s bright eyes and the surrounding fires reflecting off the thousands of shards slowly receding, replaced with her standard tent furnishings. 

Sweat, not brought on from any humidity or heat, dotted her brow. Shaken and stirred from her cryptic dream, Byleth shakily grabbed for her pouches. Armor still on, save for her tail, there wasn’t much she’d need to do to get ready in the morning, and in the event of a night ambush (unlikely, given Solon), she would have been prepared. There was a battle today, and the demon was determined not to let a silly dream deter her from one of the only things she genuinely took pleasure in. 

… But fuck if the dream didn’t unnerve her. 

That was a problem for tomorrow Byleth. Today Byleth was ready to take the world by _storm._

\----

Storm was an apt description. Destructive, unfeeling, and undaunting in the face of opposition, Byleth felt her claws cleave through flesh as if slicing hot butter. Blood spilled to the ground as freely as ale in a tavern, oozing and thick as it stained the grass below. The large expanse of Gronder was more than enough room for the demon to truly let loose, slicing, and cutting with claw and sword alike. Whenever a soldier or mercenary would fall, three more would take their place. All it did was fuel Byleth, her power growing stronger and stronger as victory and blood amassed within her grasp. This… _this_ was an offering. She owed Seteth for this opportunity. Nothing could stand before her, and if a rival had even a modicum of courage leftover after gazing at her terrifying visage, it was all but lost when she mowed them down. She felt _powerful_. She felt closer to herself. 

The only thing that differentiated this from one of Byleth’s pre-mirror dreams were the children. 

Some were adults by age’s term, but they’d not seen the likes of war before; therefore, they were still young and green. After today, Byleth would see them in a new light. As vicious as demonic life could be, there was much to be said about respect earned after one’s first battle. She was learning many things about those entrusted into her’ care,’ but even more so of the contract holder that kept her truly at bay. Whenever she would leave her red haze of destruction, her practiced eyes would find Seteth across the field, his gaze stony and fixed as he focused on the task at hand. His proficiency with his lance was admirable, and she felt the respect growing. _If only he could put away that senseless attachment_. He’d be almost as well oiled a machine on the battlefield as she was. 

Respect was earned. Respect would be given, at least. 

Despite the blood and grit, she could still taste him on her lips, a lingering sensation that addled her thoughts and made her heart speed with adrenaline. It was an apt stimulant, given the scenario. The blood roared in her ears as she tucked them close to her head, though a nick or two in the flesh would add to her intimidating appearance for sure. No, efficiency was best in both war and Seteth. The methods earlier this morning were a bit underhanded, given his pleas for secrecy and slow speed. Still, when Byleth was incapable of articulating what she felt, actions spoke far louder than words. She couldn’t put into words how she felt for the irritable Priest, but at least she could act more in line with the feeling. Besides - articulation required more thought. Who wanted to sit around and discuss feelings when there was work to be done? It was work Byleth enjoyed. Tactical assessments of the students, massive amounts of unadulterated carnage, and what would undoubtedly be an enjoyable and rowdy celebration after their inevitable victory. 

Dimitri overestimated the swing of his spear, leaving a large opening that Sylvain covered with a quick swipe of his lance. Flanked by Caspar, the offensive students were holding up well within their contingent. Per Byleth’s suggestion, they were sticking together in a ring style formation, keeping both Annette and Mercedes within the confines of the circle. From there, Byleth was expanding out in an arc, returning only to reassess the battle from a controlled vantage point. The students were encouraged by her presence, striking out harder and faster out of self-preservation and an urge to impress. Something about their ‘professor’, and Claude’s impeccable charisma, was keeping them going. One of his arrows whizzed by Byleth’s nose, embedding itself in the eye-socket of a soldier boldly rushing the demon. A whoop from the student confirmed her suspicions, and a slight smirk rose to her lips. _Good._ The undesignated second favorite, Felix, danced around with his double sheaths and sword, striking hard and fast on the opposite side of Dimitri. Between his yells, expertly timed dodges and defenses, and quick calls, Dimitri was kept in line. Mercedes was in the center ring, casting healing magic as needed. The strict orders to avoid Byleth at all costs with her magic had been followed so far, but the Ashen Demon kept an eye out. She wouldn’t put it past the meek girl to accidentally try and heal her if she sustained an injury. Her heart was too soft. Truly, Byleth also wouldn’t put it past her to heal the enemies once they were done. 

Everything was going well. 

Until it wasn’t.

“ ** _ASHEN FRAUD!”_ ** A grating voice rose over the metallic clang of metal and the anguished screams of fallen soldiers. There was no mistaking it, even with the chaos of the war around her. The Death Knight was calling out to her, though it took her a moment to pinpoint where the cowardly fiend was howling from. It was about time the craven ass showed up. He wanted her title? Her power and notoriety? The bony monstrosity would have to pry it from her cold, dead claws. 

It took every ounce of self-control Byleth possessed not to transform now, flattening soldiers in her wake from both sides, to devour the main source of her discontent. All of her problems would be solved if she got rid of the one thing she couldn’t - the lack of control. She was unable to hurt anyone from the Monastery. 

_No matter_. _He does not deserve a quick demise. I will make it slow._ Byleth glowered to herself. The moment their eyes met, The Death Knight cackled. 

“ _ **I**_ ** _was beginning to wonder when our blades would cross. I have seen your power and have been looking forward to another opportunity to deny you the satisfaction of dispatching me.”_ **

The more The Death Knight spoke, the angrier she got. _I will make it painful. He will beg for mercy, and he will find none._

Unaware of the internal dialogue Byleth was having with herself, The Death Knight continued. Her eyes failed to stray from his, mental hackles raising as her bone blade began to reform once again, piece by piece. Perhaps she could add some of his skeleton to her blade’s edge. No, she would not give him such an honor. 

Gaze unwavering, she maintained his as more of his reinforcements gathered around him. Their faces blurred in obscurity. They were lesser beings, unimportant in the grand scheme of things. Only two individuals truly mattered on this battlefield, and only one of them would live. 

“ _ **I**_ ** _regret to inform you that my contract holder has considered you too much of a liability to keep alive."_ **That much had been a given, yes? **_“As much as I like to play with my prey, we will have to do this a different way. I’m sure you understand.”_ **His grating voice parted the skirmishing sea, creating a line of sight for the two demons to see each other in their full, bloody glory.

Byleth didn’t understand his babble. There was only one way they’d finish this. _I will make an example out of him, for I am-_ Byleth’s thoughts stopped as The Death Knight’s arm raised, holding Seteth by his hair, battered and bloody body half held as his knees scraped the ground. He was conscious and alive, but barely. 

_No. No, no. No no no no-_

Byleth understood as The Death Knight raised his scythe to Seteth’s neck. “ ** _Ashen Fraud. This ends now. The moment this pathetic mortal breathes his last breath, your contract is forfeit and you’ll return from where you came. I only hope watching him die will fill me with enough satisfaction, since I am being robbed of yours."_** Despite his grand words, there was no movement of the weapon, though she could tell it was flush against his skin. Seteth’s eyes fluttered open as his hands gripped against the scythe, trying to push it away. The scent of his blood boiled her rage over as her body began to shake. Something within her was taut, ready to snap.

Fangs bared, The Ashen Demon glowered, eyes glowing amidst the dust of the battlefield. “ **You let him go right now, or I will rend you** ** _limb from limb_** **you-”**

“B-Byleth.” Seteth’s choked whisper was barely audible, her ears flicking forward desperately to catch the slightest word from him. The roar of the battle threatened to take his words from her, almost as loud as the thundering heartbeat in the tufts of her ears. “Take the students a-and… retreat.” The Death Knight cackled, but remained still, drinking in the torment of the situation as Seteth relayed his wishes. “Get out of here, make sure they survive… My journal, t-too-” 

“ **No.”** The word seemed to stop the fighting around her, the mercenary army, and the monastery knights looking up to see the conflict between the two powerhouses. If there was any unease, it was well hidden by dirty helmets. “ **Make sure they survive yourself. You do not fall here. I will not allow it.”** Something flickered across Seteth’s face, but Byleth was unaware of the emotion’s name. She had not seen it before. 

“ ** _Pity, your words are empty. As empty as my expectations from you. I hold the power now, Ashen fraud. Not you.”_** The Death Knight hissed with glee, tightening his grip on Seteth’s head. With a flick of his wrist, Seteth’s chin was pulled back further, exposing his neck for the world to see. “ ** _Your wings will not carry you here in enough time. But please - I invite you to try. It will be delicious watching your agony as you fade from this world.”_**

Her wings unfolded with a sharp crack as the leather pulled taut, readying herself to speed forward and prove the rival demon wrong. “ **I will drink from your skull, only to spit out the contents out of spite.”**

“Byleth, no...” Seteth’s _plea_ almost sounded desperate. “The students-” His sentence was cut off by a sharp yank of his hair. It devolved into a growl of pain as Seteth gritted his teeth. It was all to rile up Byleth, no doubt, and it was working in every sense. Something cracked behind her, or at least, it sounded like it was behind her as she clenched her fists. Everything felt as if it were balancing on a wire, ready to tip in any direction at any moment. All it took was a whisper, a breeze, a sign. Byleth’s muscles tensed as she prepared to dash. 

Her eyes met one of Seteth’s, halting her in her tracks.

“Damnit, Byleth!" His body wrenched as he coughed, a trickle of blood beginning to slide from the corner of his mouth. His pain must be hers. It must've been the seal on her skin, that had to be the only explanation for the agony in her chest. "*Agh* No... Ashen Demon! I _command_ you to take the students and flee. Leave me, for the love of Sothis, _Leave!_ **_Now!_** _"_

The command seized her by the throat. 

**Notes for the Chapter:**

> Thank you so much for sticking with this story, oh my goodness. This chapter subject to small edits - I wrote this over my night shift ROFL
> 
> Things are wild on my end - travel medical is fun but definitely has its drawbacks. I've 90% recovered from COVID and only have some breathing problems now. I've been back to work and am finishing up my contract in Boston before moving down to South Carolina for a permanent job at a hospital in the city. I'm excited to plant roots and stop travel for a bit. That's good for me and good for Ashes! I've known how this was going to end for a while, and it's super nice to get stuff on paper. COVID is still very real, and very dangerous, so please continue to implement your social distancing and mask-wearing. We'll beat this together, just like, uh, hopefully, Seteth and Byleth defeat The Death Knight. Your support and comments mean the world to me, and I hope I haven't kept you waiting too long! 
> 
> ALSO SHOUTOUTS TO 66,666 WORDS FOR OUR DEMONIC FIC ROFL (I totally added 12 words after publish so that we could be freaking ridiculous)
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	16. Penultimate

**Summary for the Chapter:**

> Byleth must make a choice, but some minds are already made up.

**_“Father?”_ **

_A young Byleth sat on the cold, cobblestone floor beside King Jeralt and his throne. Her delicate hands, yet to be scarred by years of war and strife, played with a soft toy of woven fiber in the shape of a bearcat, stuffed with aromatic herbs. Jeralt’s eyes looked down, though his chin never dipped. Never fell. There was pride in being a demon, and there was pride in being a leader - something he made sure that Byleth remembered daily. “Yes, Byleth?”_

_“_ ** _Why do people listen to what you say because of your chair?_ ** **“** _There was a basic understanding of hierarchy and fealty, but why was Jeralt in power in the first place? What put him there, and what kept him there?_

_The corners of The Blade Breaker’s mouth tipped up in a subtle smile as he reached down and plucked the young Byleth from her toys, placing her on his knee in the empty throne room. “It’s not about the chair, hatchling. It is about respect. Strength is important, but there are many strong individuals not worth respecting. Remember this, Byleth. You will be strong, and you will grow into your title, but that strength is worthless if no one respects you. It is what you do with your strength that determines true power.” Heavy words for such a young child, but in a society where so much was placed into power… it was best to teach his hatchling early. “Are you listening to me, Byleth?”_

_Byleth’s tiny hands hide the bearcat behind her back as if he hadn’t seen her playing with it as he spoke. Her tail flicked back and forth as she lied. “_ ** _Yes, father. So we listen to people we respect?_** **“**

_Jeralt chuckled. “Yes, although there are some exceptions to the rule. When we are called to assist the humans, if they command us to do something, we have to do it.”_

_“_ **_But why? What if they’re not good people? What if I don’t respect them?_ **

_“Because we must. If we didn’t listen to them, we could run around the human world without a care in the world.”_

_The young demon looked around, curious if anyone else understood how ridiculous her father sounded. Her face betrayed no emotion, but it was clear she was confused. “_ **_But… why? That isn’t bad, isn’t it big and pretty there?"_ **

_The weary king ran a hand through his hair before carefully ruffling hers, careful of the tiny nubs of her horns slowly growing in. “It’s hard to tell when you’re trying to rile me up with a joke if you look so serious all the time. I suppose you get that from me. Yes, dear, It is pretty there, but it is not our home. Their commands keep us in line. We are stronger than them. It is their fear that binds us, in a way. Fear of our strength, fear of whatever made them call us in the first place, fear for those that they love… We must respect that and not take advantage of it. Now-” Jeralt set her down among her toys. “-don’t worry yourself with talk of fear and commands. You are young, and it does not concern you yet. Bearcats are far more interesting.”_

\----

Seteth’s fear gripped at her heart like a vice, squeezing the breath out of her and turning every drop of blood within her veins to ice. Their shouting across the battlefield had all but halted the combat in their immediate vicinity, monastery members too afraid to make another move. If Seteth fell here, it would all be over. Eyes flicked back and forth between the two demons, and Byleth could feel their desperation crawling up her back. 

Their fear. 

All of it. 

It was a thick smell, heavy with the possibility of loss. The more you had to lose, the stronger it was. Words from her father seemed so far away, hundreds of years long-buried to memory, but they rang true to this day. He was so wise. What would he do in this situation? Byleth regretted not asking more questions as she grew. The truth of the memory made her body shake, gritted teeth threatening to cause a headache if she ground her fangs any harder. Seteth was a simple glide away, mere paces if she broke out into a run right now. Seeing the cold metal of The Death Knight’s scythe against the soft, vulnerable flesh of his neck… There were too many emotions. 

These feelings must be Seteth’s, right? This nauseating sense of fright as one stood on the precipice of indescribable loss. He had so much to lose - Flayn, the Monastery, Rhea, and the students. This palpable worry and the dire circumstances together were a tragic tale; it was no wonder he was afraid. 

_No…_ _this is no crest. No sigil._

 _I think… I think_ ** _I_** _am afraid._

**_“You heard your master, mutt. Turn tail and run!”_ ** The Death Knight roared with laughter, his shaking mirth pulling the scythe across Seteth’s skin dangerously. Only a thin line appeared on his pale skin - not deep enough for concern yet. “ ** _Let us see how far you can get before he bleeds out, hmm?”_ **

The bastard was having far too much fun with this. 

Everything within her body commanded her to run. Her brain, wired from first breath to that of the Ashen Demon. Her lungs, which screamed in pain as the air was all but squeezed from them. Her chest, tight and constricted as the torment only grew the longer she disobeyed. Her heart, which-

Her heart. 

What did it say?

The past few months on the mortal plane with Seteth had been a whirlwind of new emotions and experiences. She thought she had experienced a sunrise, but nothing compared to watching the sunrise above the horizon in the sky with Seteth. Food tasted better with him around, and a shared meal was akin to the rarest meats she’d ever devoured. The exhilaration of battle filled her with power and energy, a rush like none other until the electricity she felt when Seteth’s fingers interlocked with hers. The feeling of security and safety in his presence and the intrinsic ease to let her guard down, both physically and emotionally. This ‘contract’ had been an entirely new list of firsts, fit for a mortal lifetime. He did not make her feel mortal, but he did make her feel alive. 

_Alive._

That preservation of life, and something else - the absolute desperation to keep those cared about safe. She felt it to an extent with Flayn when she was in danger. She’d marked it off as distant blood ties, or a favor returned from the child’s simple act of kindness, but there was no doubt an undeniable line that had been crossed. 

Byleth would never be able to leave this battlefield. 

The pain that rumbled in her chest and threatened to steal the air from her lungs, reverberating through her limbs with every distressed heartbeat, would not come close to the anguish knowing that she let Seteth perish on this battlefield. Too much of his blood was spilled already. She should’ve been there with him. Lungs could burst, and chests could constrict. Claws could break, and tails could go limp. Horns could dull, and fangs could file, but her heart would never recover.

There was no room for love on the battlefield. Byleth had seen what it did to the careless. It made them make mistakes. And yet… She did not need to speak the words aloud or to name it. There was no struggle for articulation and no searching for a name. Byleth knew what this feeling was, and knew where the fear took root. 

The more you had to lose, the stronger it was.

Her body was moving before she willed it. The last of her ability to stop time began to distort the world around her, bright and vivid colors slowly fading into muted shadows as she began to run. It would have to be enough. It would have to be enough. The sluggish movements of The Death Knight slowed to a halt, his feeble attempt to pull the scythe thwarted for now. Seteth’s gasp was frozen on his face, a look of both surprise and horror as the last thing he saw was Byleth charging.

She would make it. 

She would make it. 

She had to make it. 

The edge of her vision flickered as the command’s pain continued to rise. The longer she took, and the more energy she expended, the worse the pain would become. It slowed her and dulled her magic like a smothered fire. 

As she fought to clear the distance, it slowly dawned on her that it wasn’t going to be enough. Her chest heaved as she fought the bile that burned at the back of her throat. There was one more way to cross the distance in enough time, though the repercussions were never enjoyable. _It seems this is the only way._

She began to transform. 

It was usually something to ease into - the perfect opportunity for onlookers to see the process and flee for their pathetic lives. A powerful, monstrous show of power as onlookers could do nothing but gape in horror. It was least painful this way. However, Byleth lacked the privilege of a painless endeavor. Mid run, her limbs began to crack as the world around her shifted with her alterations. Her tail began to grow longer, wings stretching with leathery pops and groans. Her arm wrenched to the side, growing into a monstrous foreleg as her face contorted. 

That’s when she saw it. Time had stilled, but something was moving in front of her. 

Herself. 

She was the mangled, grotesque half-transformed creature from her dream. 

The Ashen Demon was staring at a mirror. 

All of the visions, all of the variations of herself she’d seen in the mirror - those were all indeed her. Her usual self, horns and all, was the form she enjoyed the most. A human Byleth, there to challenge all her preconceived notions of emotion and personal growth. And this creature she was, even for a brief moment. There were in-betweens, and there were facets of her personality she never knew existed. Demons had been taught they were one thing. 

She was The Ashen Demon. 

But she could also be Byleth. She could be a teacher and a fighter. She could be a scout or a taste tester. She could speak to dragons, or become one.

And she could _love_. 

Akin to her dream, Byleth charged at the mirror, bracing herself as the transformation neared its end. The reflection grew closer and closer, threatening to charge into itself as the dragon reached the reflective edge. 

Time returned to normal as Byleth broke through her mental barrier, the cracking of glass muffled by the cracking of The Death Knight’s armor and bones beneath her jaws. Seteth gazed up in abject horror until the beast’s coloration and Byleth’s missing form helped him put the pieces together. He was dropped unceremoniously, the scythe clattering to the ground next to his slumped body, too weak to stand for himself. Byleth’s proper form had been a secret for Seteth and an assumed weakness for The Death Knight to exploit. With a shake of her head, Byleth sent the battered demon flying across the field, armor clattering against the ground as he skidded to a halt. 

The thick, leathery wings on her back weren’t just for show. As they unfolded, the sun for the onlookers underneath blotted out temporarily. It was hard to tell whether they were emboldened by such a creature on their side, or terrified alongside those rallying for Solon. If they were not terrified now, they would be soon. The Ashen Demon stamped a foreleg against the ground and _roared_ before galloping and taking air. Soft underbelly safely out of reach of lances and pikes, her sights turned to the shaky demon, slowly rising to his feet. 

“ ** _That is quite a secret, Ashen Demon. When I take your title, will I get the time power as well?”_ **

“ **THOSE ARE BOLD WORDS FOR A DEAD MAN, DEATH KNIGHT.”** Byleth retorted, deadpan upon approach. With no scythe to assist him, The Death Knight unsheathed a sword from a gnarled and twisted scabbard at his side. The ebony blade seemed to be void of all light, a stark comparison against the bright sun that loomed overhead. No matter the demon’s tools, he would fall all the same. 

He tried to prepare himself for Byleth’s attack, but there was not much he could do to defend against a beast of such size. Her gaping jaws snapped at him, neck outstretched to close the distance at an alarming rate. The Death Knight managed to jump out of the way, slapping his void sword down at her scales. Catching a groove underneath, it sliced down the side of her neck. She hardly felt it - honestly, the pain from the command weighed more on her compared to this mere flesh wound. 

“ **I TIRE OF THIS GAMES.”**

“ _ **Y**_ ** _ou tire because you are weak. Your bonds make you weak.”_ ** Antagonizing Byleth as a distraction, The Death Knight raised an arm to send a blast of magic towards Byleth. Body too large to dodge quickly, she took the hit. Her scales absorbed most of the impact, though she could tell it would smart once the adrenaline was out of her system. “ ** _Your attachments to these pathetic humans you have been around will be your downfall. Your father would not recognize this weak creature before me.”_ **

“ **YOU ARE WRONG.”** Byleth’s tail lashed, slamming into the demon’s side as he lowered his arm, sending him rocketing towards the edge of the battlefield. “ **MY BONDS MAKE ME STRONG.”** With a mighty push, Byleth jumped towards the impact crater The Death Knight had caused after such a harsh blow. Her clawed leg pinned him to the ground, putting pressure to sink him further into the soft, wet ground. “ **MY RESPECT FOR THE HUMANS THAT HAVE EARNED IT MAKE ME STRONG. MY FATHER WOULD RECOGNIZE ME, AND BE PROUD, UNLIKE WHATEVER YOU HAVE BECOME. IT IS WHAT YOU DO WITH YOUR STRENGTH THAT DETERMINES YOUR TRUE POWER. IS THERE A SINGLE SOUL HERE THAT RESPECTS YOU, DEATH KNIGHT? WILL YOU BE REMEMBERED, OR WILL YOU FADE INTO OBSCURITY AS YOU ARE REBORN?”**

The dragon’s head lowered to pick up The Death Knight with her teeth. It had never occurred to him, in his final moments, that perhaps she’d kept a secret far more potent than time from him. Far beyond the powers any demon truly possessed. As Byleth’s teeth sank deeper into his skin, it was clear he’d genuinely been outmatched. Black ichor seeped from the wounds, dripping down to the bloodstained battlefield and down Byleth’s sleek, black scales. 

“ ** _I underestimated you, Ashen Demon._** **_You are a beast of skill, and worthy of your title.”_** She could not see or smell any fear on him, but his lack of struggle was disappointing. A weak apology for a weak demon. “ ** _It is a mistake I will not make again.”_** The Death Knight wheezed from her bloodied mouth, eye sockets dim as he hung from Byleth’s teeth like a pathetic ragdoll. Oh, how she _wished_ this could be drawn out. To hear his piteous cries for mercy in a cavernous ruin, the screams echoing through dilapidated halls. He wronged her humans, and that was a grave mistake. Did he want to see The Ashen Demon in action? He would’ve been granted such an audience for a much longer duration befitting his transgressions. She did not have the luxury for such a moment, however. The command still took hold, and the large dragon’s flank began to shake with pain as she fought back. His words were an understatement, however.

“ **YOU ARE CORRECT. I ONLY WISH THIS WAS MORE SATISFYING.”**

Her voice was a rumbling growl, subtle as thunder with the power to back it up. The large dragon’s jaws snapped together, and The Death Knight fell to the ground in two. Byleth’s cavernous maw opened and the skin of her throat warmed as fire bubbled in the back of her mouth. Once warm enough it was released as a torrent of flame on the separated demon, Byleth smugly watching his body turn to sludge and ash. It was only after that she felt her legs give before the great dragon fell, shaking the ground on impact. As her eyes closed, she saw Monastery knights across the field, rushing to Seteth’s side to help him up. The irony of the moment wasn’t lost on her. Wasn’t this similar to the night they’d met? Seteth’s head turned, his green eyes meeting hers as everything went black. 

This was not a loss. 

This was real victory.

**Notes for the Chapter:**

> Apologies for the re-upload! I received some good feedback regarding the length and pace of the chapter, so I fixed the issues and reuploaded what I could fix. This was inspired by one of my favorite Mumford and Sons songs, which really kicked off my idea for Ashes in the first place. 
> 
> [Slip Away - Mumford and Sons](https://www.youtube.com/watch?v=B8N6VWnqKBs)
> 
> That being said, I'm a nerdy FUCK and really enjoy making music videos in my head and since I can't really draw I wrote it all out. It's here if you want to see. 
> 
> [Poorly articulated Mental Music Video for this Chapter](https://docs.google.com/document/d/1H6BEj7u-6F8Xld52J0fR7YBwJQg9DX89mfnMwXIBFZc/edit?usp=sharing)
> 
> Thank you so much for the <3! I'm super happy to get back to updates for Ashes. Things are just getting good! Promise a Seteth POV chapter is coming.
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


	17. Aftermath

**Summary for the Chapter:**

> Seteth has a lot of time to contemplate his feelings, because Byleth hasn't woken up yet.

It felt like years had passed since Seteth tried to unravel the mystery of the underground chamber. The Death Knight resided in his mind since that day, a beacon of hate and animosity for taking away his daughter in the dark of night. That had been a turning point for many things: the way he saw Byleth had changed after she’d rescued his little girl, an enigma of ash and fire, and of course, The Death Knight’s fate had been sealed. If Byleth didn’t kill this horror, he was going to even if it killed him. 

It almost did. 

He had been too hasty, too eager, after seeing the back of the demon amid the fight. He thought his holy magic would be enough. After seeing the way it charred Byleth’s flesh in their training yard spar, he’d hoped it would eviscerate the other demon with equal ease. Where Byleth’s armor was actual metal and plate, capable of being removed, Seteth quickly found out that this was not the case for The Death Knight. In an unfortunate turn of circumstance, he’d found the demon’s secret ability. His armor seemed almost impenetrable to magic. 

The fight, hard as Seteth fought, did not last long. 

And to be used as  _ bait _ , mere emotional fodder for Byleth… it broke his heart just as much as his body. He would never forget the look of shock on her face, the way her pupils changed when he was presented as a grotesque trophy on display for all in the vicinity to look at in despair. If his body and heart were broken, everything else in him shattered when Byleth refused to listen, refused to enact the one thing he’d asked her to do if things had gone south. Take care of the students. Take care of the note to Flayn. He seemed to forget if something happened to him, Byleth would disappear, but at least getting the students as far away as possible… Their political standing would net them easy travel back to the Monastery, and he doubted their parents would bat an eye at rewarding the samaritan that assisted them. 

Everything had lined up. He would fall here, for the Monastery, and Rhea would remain as she was until someone cracked the secret, destroyed The Plague, or took care of Solon on their own time. As he bled on the grasses of Gronder, Seteth slowly came to terms with his fate. His arms were numb and broken. His lip swollen and busted, ribs cracked, and knees all but battered. The man didn’t have the strength to heal himself nor the opportunity. The only saving grace was knowing Byleth was going to turn away at some point to follow his command. He felt  _ horrendous _ for forcing her, but there was no other way. Besides - Byleth had howled at him for putting himself in harm’s way for her at Remire. The verbal lashing was one he would’ve preferred to the physical one he just took, for what it was worth. Oh, to be on the seething end of that glare one last time. To watch it soften for him, and the smirk he had grown so fond of to rise back to those taboo lips. 

Byleth had to give him this final burst of hope that his last words would make it to Flayn. 

That the future of the Monastery would live on in the students she saved. 

Please, Byleth. 

_ Please. _

It never came. Instead, Byleth did in a rush of fury and fire. Her body cracked, malforming as she took a step. His mouth opened in shock, though he couldn’t will any sound from it as the edge of his vision began to blur. The sensation, her ability to bend time to her will, was one he’d grown familiar with. It was an undignified, silent howl of shock, but frozen all the same. What was happening? What did she have planned? Why didn’t she just  _ run _ as he told her to?

It felt like an eternity before the world began to move again. Seteth could have lived another hundred lives, plagued with the knowledge he’d never know what truly happened on that battlefield until time started again. He knew it was a delusion from blood loss and a lack of healing. The tight grip on his throat, the eerily cold steel pressed against the soft flesh of his neck, grew harsher as movement returned to their surroundings, but before the blade could dispatch his life, a massive pair of jaws locked around his captor. 

The dragon, massive in stature and careful with massive fangs, threw The Death Knight across the field and immediately lumbered after, practically drooling with hate as her eyes honed in on her prey. The black mane and tail, the wings… her scales… This was Byleth. The transformation hadn’t been complete when time had stopped, but this  _ must _ be her. Seteth didn’t see her anywhere else - Byleth was a dragon. 

Byleth was a  _ dragon _ . 

The thought was preposterous until the pieces slowly started to come together. He never was able to see Byleth with his magic in the underground chamber… perhaps it was because she was too large? The claw marks, the ash, and fire… it would make so much sense despite the shock. His reeling gaze followed the battle between the two demons, the fierce dragon keeping The Death Knight on his toes. She never attacked him with fire, only fang, claw, and tail to keep him on his toes. Did she know of his ability? He tried to call out - warn her if for whatever reason she didn’t, but the words never left his lips. Instead, he coughed and sputtered over himself, threatening to lose himself to the spinning world around him. Seteth closed his eyes, trying to will any magic to his fingertips. 

It never came. 

A blast of heat wafted from the side where they’d been fighting as Byleth burned the remains of The Death Knight to a puddle of sludge. It seemed he had been protected from a short burst of magic, but the consistently volcanic flames that spewed from Byleth were enough to obliterate the fiend where he rested in pieces. There would be no recovering from that. Not even Byleth would have been able to walk away from an attack like that, and she was the strongest thing he’d had the privilege of laying eyes on. 

_ Byleth. _

Even now, her form was striking. It was a different beauty, seeing her as her true self, as though he should have known this was what she truly was. Speaking to Saint Pebbles, flying, her horns… it all made sense and tied up the bow around the enigma that was The Ashen Demon. 

His eyes caught hers as he was pulled to a sitting position by a knight, multiple pairs of hands on him as they surged him full of healing. Bones cracked, their fragments attempting to fuse back together, and his wounds closing up with the magic. The magnificent beast across the field fell, but the battle surely had been won. 

“G-Go…” His weak hand pointed in her direction, and at the fleeing mercenaries of Solon’s army. Capitalize on their fear, and form a perimeter around the reason they’d won this battle. 

Around the reason he was still alive. 

Though he couldn’t speak, the gesture was enough and the knights started shouting to one another, forming ranks to surround the downed dragon, the rest chasing after the mercenaries and taking whatever prisoners they could for questioning. Seteth’s students, more aptly Byleth’s, ran to his side. Their wide eyes and shaking limbs suggested shock and adrenaline, but they knew what they were getting into. Perhaps not the  _ dragon  _ part, but at least the carnage. They were strong children - no, young adults - and they would be fine. 

“Seteth!” Mercedes dropped to her knees and moved to heal Seteth as well; the rest of the students forming around him to help protect their leader. 

“Give him some air, Mercedes. We can’t crowd him.” Clade had a casual air about him, but the Priest had been around him long enough to know the concern that he tried to hide on his face. His eyes continued to flick between Seteth and Byleth as if splitting his attention would keep them alive and well in front of him. 

“Help… her.” It took a moment, but Seteth was able to croak out the words, rolling a shoulder that had been popped back into place. He was thankful that he hadn’t cried out in an undignified way, but he knew those surrounding him would understand and withhold judgment. Still - Seteth couldn’t help but nurse a bit of his wounded pride. He’d been bested very quickly for all to see. Sure, he had taken down Byleth twice, but that was without this destructive power. I’m _ beginning to believe I would never have been able to beat her if she’d truly gone all out. _

Claude flashed him a grateful look before breaking off into a run towards the dragon. The boy wasn’t known for his healing magic, but every bit helped, and they seemed to at least have a bit of camaraderie. Who knows when Byleth would wake up? It was good to be among friends. 

They were friends, yes? He certainly hoped so. Seteth knew the numb feeling in his lips was from the swollen split, but he couldn’t help but feel the same tingle when her lips had left his mere hours ago, in the dark of night before the watch had shifted. A shaking hand rose to his own lip, a gesture he saw Byleth do multiple times before he healed it himself. 

\----

Their casualties were minimal, which had surprised Seteth. They held their own remarkably well against the horde of enemies Solon had thrown at them, but loss of life was inevitable. The contingent held vigil over the broken bodies of their fallen comrades, a traditional prayer spoken for them to guide them to the open hands of the Goddess. Even if Seteth knew the truth, now was not the time nor place to explain what he’d learned of Sothis herself, and the kinship she shared with Byleth’s kind. 

Byleth had yet to wake up but eventually reverted to her usual body. It seemed to be a slow regression, perhaps to save her body from more pain? The initial, quick transformation seemed to be painful if the anguish on Byleth’s face before time had frozen meant anything. She’d been moved to their camp, set up in Seteth’s tent with a ring of knights around to keep them safe. Solon had been thoroughly defeated with the fall of his precious Death Knight, but Seteth took no chances. They’d almost lost with his failure, a bad call on the battlefield, and he wasn’t about to make the same mistake again. 

There was no bath to truly clean Byleth, but he did his best with a rag and bucket, cleaning the remnant blood off her face, claws, and hands. No other skin was visible, but he wouldn’t do her the dishonor of removing her armor and leaving her exposed when he was unsure when she’d wake up. Instead, he sat on the ground beside the cot, leaning against it so he could look up at the ceiling of the tent. They’d break down the campsite tomorrow and begin their trek back to the Monastery. A victory under their belts had morale at an all-time high, but Seteth and the students harbored rough waters as they navigated the emotions surrounding their sleeping demon. 

\----

The students, spry and full of energy, were put under the care of Seteth. The knights would never admit it was also to keep extra eyes on the pride of the Monastery itself, but Seteth appreciated their concern. A horse-drawn wagon followed the front-line, wooden wheels clacking against the cobblestone as they progressed. Mercedes and Felix were inside with Byleth, who’d yet to wake up. Everyone had been adequately healed, not a blemish or scar in sight for those that survived. The names of the fallen had been scrawled into a plaque they would put up to commemorate the dead in the sanctuary, but Seteth wished he could have done more for  _ any _ of them. 

Even the ones that had lived. 

Had he really been ready to give up so quickly? His life had been practically forfeited, so easily tossed aside for the chance his final words and the students would have made it back to safety. He’d done all he could to ensure that, but the headstrong demon had other plans. Seteth stacked this phenomenon up to guilt, netting his only real mistake being his underestimation of The Death Knight himself. He hoped Byleth would be awake soon to list off all of the reasons he was an ‘idiot youngling’ for his choice. Yes, this went along nicely with his attempt to save her from the Death Magic in Remire. He could almost hear her: “ _ Seteth, you are so quick to throw your life away! You must live it out of spite!”  _ or something of the sort. At least his impression brought a small smirk to his face.

It hadn’t gone unnoticed, unfortunately. 

“Think of something funny, Professor Seteth?” Claude inquired from his left, Dimitri looking over to be in on the joke as well on the right. Leave it to Claude to pick up on the tiniest of mannerisms. 

“Just thinking about how we are all going to get yelled at once Byleth wakes up.” It wasn’t technically a lie. He spared a glance over his shoulder at the carriage behind him, eyes lingering for a moment before returning to the road ahead. Claude shared in the silence, but not too long after he was speaking again. 

“I didn’t expect the uh…” Claude dropped the reins of his horse to make a set of horns on his head with his hands in an attempt to mimic Byleth. He opened his mouth to ‘spew fire.’ 

The Priest shook his head. “Nor did I.” 

“You didn’t know?” Dimitri entered the conversation, his outburst dripping with incredulous surprise.    
  
The Priest shook his head again. “Not a clue.” 

“I guess that chest thing doesn’t tell all.” 

Seteth allowed himself the smallest of chuckles. “Hah. Claude, if it did, perhaps we’d have avoided quite a few misunderstandings.”  _ Perhaps I would have known her intentions at that moment on the battlefield, as well. _

“Will we truly understand the ways of Demons? Or of women?” Dimitri let out a wistful sigh. 

Claude met it with a barking laugh. “Dimitri, what happens when they’re one and the same?” 

Seteth groaned. “A massive headache, that is what.” Dimitri chuckled and slowed his horse’s pace so that he could ride alongside Sylvain behind them. 

“At least she’s one heck of a dance partner; you two were killing it.” Claude winked, slowing his horse as well to leave Seteth to stew in the realization Claude heard wind of their rooftop excursion. When Seteth turned to look over his shoulder, he was met with the trademark shit-eating grin Von Riegan was known for. 

\----

Aside from the occasional bit of socializing, the trip was unremarkable. The nights were filled with revelry and excitement, troops abuzz with their victory, even if it was entirely slated on the quick thinking of one individual who had zero actual affiliation with the Monastery itself. Seteth wouldn’t be the one to rain on parades or sully their mood. Let them have their fun - they’d set out most of what they had hoped to accomplish. Any chance of finding Solon, if he was even around, diminished the moment Byleth’s proper form had been revealed. 

How could something so powerful and destructive be housed in something so… calm? Mind you, not while Byleth was awake. She seemed so peaceful as she slept on her side, positioned carefully not to rip any linens with her horns. They’d been riding for days, but the end was soon near. The Monastery would breach over the horizon tomorrow, and things would go back to a sense of normal until their next battle plan was set. Seteth knew he should be excited as well, Goddess knows the revelry outside was borderline infectious, but it was not befitting for a man of his position and stature to engage. Besides - it was hard to feel such excitement as Byleth still slept. 

“Why did you ignore the command? Is this not the  _ very _ thing you snarled at me for? I believe you  _ pushed me _ , of all things.” He spoke aloud as if Byleth were listening. He waited to hear for the jingle of her earrings as her ear shifted, but no sound greeted them from within the tent—just the muted songs from outside, and the occasional rustling of the grass. 

“I know you will wake, and I am not worrying as if you are not capable of amazing feats of strength and self-preservation, but… I guess I just want to understand.” There was only one upside to Byleth’s condition. All of the emotions Seteth was feeling were his own. Byleth had it difficult when both were awake - having not experienced the myriad of emotions she had before coming to the plane. She had a lot to sift through. In the tranquil quiet of their own shared space, even amongst the chaos outside, Seteth could finally sit and process his own emotions. 

How far had they come? He couldn’t stand the demon at one point, calling her a beast or creature. Byleth had taken every opportunity to annoy him post-binding that it had been difficult for Seteth to think, let alone function. All of that frustration had culminated into one raw fight for the respect that he’d somehow won. At first, it felt like a full victory, but now it felt hollow. She would have destroyed him with her tail - no, a single claw - had she transformed. Garreg Mach would be in shambles, and the progress in keeping Flayn and Rhea safe would be non-existent. It was so easy for his mind to think of what could have been and to fret on every possible danger that could have befallen his students and Rhea, or worse, his daughter. 

The very thing he couldn’t stand had ended up being salvation for them. How ironic. 

At what point did that all change? It was slow, months and months, no doubt. It had taken a month for him to work up the nerve to give her a task, only once he was sure she wouldn’t ruin it to spite him. And yet, in doing so, he’d inadvertently saved his daughter. Everything good that had happened in his life in the past few months had been because of Byleth. 

Flayn’s safety. Saving Remire. Flying with Saint Pebbles, and talks of battles over picnics. Moonlit dancing. Pulled glasses and chin kisses. A cold, scaled tail wrapped around his leg. A shared glance across a chaotic battlefield as Byleth sprinted towards him. The revelry outside.

These things had only happened once, and yet they burned in his memory. No seal could’ve done that. No magic could have. These were the imprints left by the demonic entity sleeping on the cot he was leaning against. Even the simple joys in life, such as watching his students grow or hearing Flayn hum as she made more chocolate to give to both the demon and the students, was aided by Byleth.

And the scariest thing? 

He couldn’t have planned a single one of these things. No amount of planning in the world could have prepared Seteth for the turn of events. It was everything he could do not to exist in a constant flabbergasted state. All the work he put into trying to stay ahead of the curve when it came to extreme, life-changing events around the Monastery was worthless. Byleth simply shattered all of that. His preconceived notions about demons, his expectations… everything. 

He’d asked her what they were in a fit of frustration, but he’d yet to honestly sit down and think about what she was to him. More than acquaintances, yes. Dare he say, friend? Does one kiss a friend? Not in the way he occasionally dared. Was this even something to be entertained further? Byleth put her life on the line for him - the gesture hadn’t gone unnoticed. It had been unexpected, though. It did not fail to add another layer of complication to the increasingly difficult situation they found themselves in. 

Conflicted feelings made for difficult evenings and Seteth wanted nothing more but to reach over and intertwine his fingers with hers. She had no way of saying no, even if it was to something as simple as this, so he refrained, timidly searching his feelings further as his mind swirled into the night. Seteth had a lot to work through, and a lot to think about, but he couldn’t bring himself to leave. He didn’t remember falling asleep, but he was woken hours later at first light, the contingent ready to finish their journey back to the Monastery. 

\---

“The moment she wakes up, send for me.” 

“Yes, Priest Assal.” 

It was unfortunate, but life had to return to normal at some point. Byleth had been asleep six days total when they arrived back to Garreg Mach, and there was no way in the Goddess’s name he was going to put her on the floor. There was a vacant tower room in the neighboring spire, so he’d taken it upon himself to move her ‘nest’ onto the bed and to have Byleth placed as gently as possible on top. Seteth wasn’t far away, only a few doors and a few flights of stairs, and the demon would have her privacy and chaperone until she awoke. If she wished to move her things back, she was more than welcome, but it didn’t feel right. 

Seteth ignored the voice in his head telling him it was because he’d be awake all night watching her, hoping she’d wake up. 

Diving into his studies after a day of rest with Flayn seemed like the best distraction, so on the seventh day of Byleth’s sleep, he put his courses back on the roster. The students flocked to class early, though he knew it had nothing to do with the curriculum and everything to do with their intense want for battlefield recollections. 

_ “How did it go?” _ _  
_ _  
_ _ “Did you defeat the army?” _

_ “I heard that you turned into a dragon!”  _

_ “No, stupid, the story said he turned into a turtle!”  _

_ “I thought it was a gryphon?”  _

  
  
Their chatter amused him, their youthful energy adding to his dwindling energy. While he was unaware where these rumors came from - some of them bordering on the line of  _ absurd _ \- he merely waved it off. “It was a resounding win for the Monastery, and another step closer to healing the Archbishop. I did not turn into a dragon, or a turtle, or a gryphon. Though if I had to choose, I would prefer the dragon. I find them rather aesthetically pleasing, and I would like to breathe lightning.” 

His veiled humor was enough to satiate the class and get along with his lesson plan quickly enough. The moment he set down the chalk and closed his book at the end of the lecture, something  _ shifted. _ The sigil, the complicated crest of interwoven arcs and straight lines Byleth had put on him in return, flared to life with a bright red hue. The bond felt strong once again, broadcasting both party’s confusion before it dawned on Seteth. 

She was awake. 

Seteth practically dropped his book and began to run out the door, much to the surprise of the students funneling  _ in _ for the next class. He barely felt his lungs screaming for him to cease sprinting, nor did he hear the caretaker he’d put in charge of Byleth calling to him as he ran past. He knew what she was saying, but he felt it before she’d even left the room to find him. Only a few doors, and a few flights of stairs, separated him and he wasn’t about to dawdle. 

What would he even say? What  _ was _ there to say? How do you convey such relief and gratitude for a mortal enemy? 

His steps weren’t silent as he clamored up the wooden stairway, hands eagerly pulling himself up the railing to increase his speed. His excitement surprised him enough to make him pause as his hand hovered over the doorknob to her room. Byleth was inside - he could hear her shuffling things around. All he had to do was open this door and convey how thankful he was that she was okay. How much gratitude he felt for what she’d done on that battlefield for Garreg Mach. For everything she’d done for him thus far. 

After what felt like a lifetime through the course of mere seconds, Seteth gripped the doorknob and opened it, barging in to see Byleth slowly sitting up on the bed. Their eyes met, and the words began to flow before he could even consider them. 

“How  _ dare _ you put yourself in danger like that? What was the  _ first thing _ you yelled at me about in Remire? One of the first things you told me that night when we were sitting on the bed talking about the differences between demons and humans? Why you take pride in yourself on how you excel on the battlefield? What happened to ‘never sacrifice yourself for another on the battlefield?’” Seteth Assal knew it was hypocritical. He knew it from the depths of his soul. Why was he fussing at her as she gathered her thoughts? She deserved more than this, and yet she merely waited until he was finished. 

He wasn’t. 

“Byleth - you could’ve died had you not passed out prior. The stipulation in our contract - had you touched a single knight on that battlefield in that massive form, you would’ve died! Do you realize that? There’s no room for emotion on the battlefield!” He changed her quote a bit, emitting love. “It makes people make mistakes! What if you’d made a mistake? What if you fell, and I died? The Monastery would be in chaos, Rhea would never wake up, and Flayn would have had  _ no _ idea what happened.” Seteth stepped forward to the edge of the bed, pinching the bridge of his nose as his voice raised with concern. “I thought you were better than this. I thought- what would’ve happened? You were asleep for days and we couldn’t wake you - and  _ Goddess _ , the way your body warped as you changed!” He was pacing. “I think I preferred when you traded no emotion in exchange for life-preserving choices…”

The Ashen Demon watched him for a few moments before reaching out with her tail to pull him into a sitting position on the bed near her. She would be well within her rights to be angry at him; he had put a command on her, after all. And yet, all she did was smirk per usual. “ **I do not prefer that.”** Her arms reached out and pulled him into a hug. “ **I’m** **glad you’re safe, too.”**

The parallel from Remire wasn’t lost on him as he felt the emotion well up in his throat, before letting out a cracking laugh, so hard he coughed at the end as his breath returned to him. “You’ve defied everything from day one with that same stubborn smirk.” His arms squeezed around her, knowing full well she was healed from her endeavors. Seteth had made sure of it. 

“ **I just needed some peace and quiet before I woke. I would have taken an extra week had I known that was what I would have woken up to. You sounded like me.”** It was a bit muffled as the line was delivered into his shoulder, but Seteth understood it all the same. He’d grown quite good at deciphering her mumble-speak. 

“Perhaps I should’ve gone on longer. Maybe I could have gotten a month without you causing problems.” The banter was something he missed. Had he really come so close to losing it? If losing his life meant that the students were safe and Flayn would be taken care of, it was a sacrifice he would have been willing to make any day of the week. 

If not having to resort to such methods meant he could  _ live _ , perhaps this was the best outcome after all. “Byleth, I- I don’t have words, I just-” Any and everything he wanted to say caught in his throat. All the words vanished from his brain, the thoughts replaced with the emotions that swirled in his gut upon seeing Byleth again. “Words are-” He tried once more, but it wasn’t quite right. There was one more way to convey, a red emotion that blossomed from the inner depths of his chest, threatening to overflow. Seteth raised a hand to her cheek, brushing a bit of hair out of her eye as he locked his eyes onto hers. 

He moved closer, timidly at first as if expecting her to push him away. Recollection crossed her features at the ‘slow’ he’d requested for the past few months. But slow didn’t quite convey what he felt. Slow was safe, and he’d played everything close to his chest prior. Everything had been safe. Garreg Mach was safe. Hiding behind his tomes was safe. Here was danger beneath his fingertips, threatening him - daring to stain his idea of perfection and complacency. Daring him to change his sheltered outlook. His walls had been breached.  Their sigils flashed as their emotions matched, and there was a brief second of hesitation from both parties, each unsure how to proceed, until Seteth closed the distance in a desperate rush, lips eagerly meeting hers with the unrestrained passion he’d stifled for so long. 

**Notes for the Chapter:**

> <3 thank you so much for the warm welcome back to the fandom! I'm actually moving 15 hours across the country in the next few days, so gimme a little bit for the next chapter. I promise it won't be six months. ;) We earn our E rating now.
> 
> Demon Byleth AU Art provided by [Naocakes](https://twitter.com/froggykind) >> [Demon Byleth](https://i.imgur.com/XaXobFt.png)
> 
> Demon Byleth AU Art provided by [Phoenx Art](https://twitter.com/phoenx_art) >> [Demon Byleth](https://twitter.com/phoenx_art/status/1265909276918210561?s=20)
> 
> Demon Byleth AU fanart provided by [JoJoOwltrees](https://twitter.com/JojoOwltrees) >> [Byleth and Seteth together Art](https://twitter.com/JojoOwltrees/status/1223327450756780032?s=19) // [Byleth and Seteth Falling](https://twitter.com/JojoOwltrees/status/1242578353179238400?s=20) // [Flying Byleth Sketch ](https://drive.google.com/file/d/1illhNMZvxSmpmQC4rN_PAcKDwd63D9-E/view?usp=sharing) // [Byleth Carrying Flayn (Chapter 7 SPOILERS)](https://drive.google.com/file/d/1XVFCwY9FJuNP2xRnivYwr5EWJz48XsSc/view?usp=sharing) // [Byleth and Seteth - The Arrows (Chapter 8 SPOILERS)](https://drive.google.com/file/d/1etCb_OpNNxcFUayKFp5R-d3Ho8WCNjXG/view?usp=sharing)
> 
> Demon Byleth fanart by [ Bee/NowYoCandysGone](https://twitter.com/EldestEagle) >> [Demon Byleth](https://twitter.com/EldestEagle/status/1224337781910056966)


End file.
